Summarize the following court judgment. Civil Appeal No. 290 of 1979. Appeal by Special Leave from the Judgment and Order dated 25th January 1979 of the Delhi High Court in S.A.O. No. 73/78. Hardev Singh and R. section Sodhi for the Appellant. Y. section Chitaley and K. C. Dua for the Respondent. The Judgment of the Court was delivered by KRISHNA IYER	 J. This appeal is symptomatic of a social pathology which afflicts the Justice System at every level with none concerned to cure it. The extraordinary scarcity of accommodation in our country has produced the legislative and legislative phenomena of tenants ' protection laws and interminable 'eviction ' cases. The situation cries for a social audit of the explosive expansion of ruinous and pathetic 283 'rent control litigation ' and an urgent yet dynamic policy of promoting house construction for the lower brackets of Indian humanity. A landlady let out her premises to another day several years ago (1968) for a term and	 thereafter	 from time to time	 continued the possession of the tenant on fresh lease and increase in rent. Every time there was homage to the law by grant of sanction by the Rent Controller under Section 21 of the Delhi Rent Control Act	 1958. (the Act	 for short)	 as if the letting were of a residential accommodation. It is apparent that all these years an elitist 'residential school ' is being run in the premises and that is the purpose expressly recited in all but the last lease deed of December 1975. This lease recites blandly that 'the lessee requires a suitable accommodation for residential purposes '. The period of the lease having expired the landlady applied for summary eviction by application for execution a novel procedure enjoyed by the landlords of this capital city which relieves them of the need even to file a suit for eviction. The tenant	 whose expensive and lucrative school was about to be uprooted for want of habitation	 hunted for a legal plea to resist the threat of dispossession. Technicality is the unfailing resource of an Indian litigant and the ingenious defence	 among others	 was set up that because the application for eviction did not mention that the letting was 'in writing ' it was fatally flawsome. Better pleas which merited serious consideration were over ruled but this little infirmity in the pleading loomed large in the eyes of the Rent Controller who	 for that reason alone	 rejected the relief. The inevitable appeal to the Tribunal followed. An application for amendment of the pleading	 by way of abundant caution	 to make good the verbal deficiency was also made. Furious forensic battles raged and the appellate tribunal as well as the High Court allowed the appeals and the amendments	 over ruling the further plea of limitation for the application as on the date of the amendment. The worsted tenant has secured leave to appeal and there is an application for revocation of leave. We have been addressed two main arguments plus other points of lesser moment. The first is that the application for execution is defective because in the narration of facts the lease is mentioned but the words 'in writing ' are not stated. It is further contended that by the time these words were supplied by amendment of the application	 the period of limitation (six months) had elapsed and that bar prevented entertainment of the proceedings. 284 Pleadings are not statutes and legalism is not verbalism. Common sense should not be kept in cold storage when pleadings are construed. It is too plain for words that the petition for eviction referred to the lease between the parties which undoubtedly was in writing. The application	 read as a whole	 did imply that and we are clear that law should not be stultified by courts by sanctifying little omissions as fatal flaws. The application for vacant possession suffered from no verbal lacunae and there was no need to amend at all. Parties win or lose on substantial questions	 not 'technical tortures ' and courts cannot be 'abettors '. The further arguments on limitation when a vital fact creative of a cause of action is brought in by amendment after expiry of limitation is an important question which need not be considered in the view we have taken on the adequacy of the pleading. The next issue is of importance not merely for this lis but also for the sensitive application of Sec. 21 in its social perspective. The notorious rack renting and impotence of legislation against unreasonable eviction in the capital city of Delhi (and elsewhere) compels us to take a close look at the facile provision in Sec. 21	 its social purpose and functional distortion	 its potential for subversion of the statutory scheme unless	 by interpretation	 it is canalised and the 'mischief rule ' in Hyden 's case applied. After all	 for the common man	 law in action is what the court says it is. To maintain the integrity of the law the court must 'suit the action to the word	 the world to the action	 and so we have to fathom	 from the language employed and the economic	 milieu	 what the meaning of Sec. 21 is and save it from possible exploitation by unscrupulous landlords for whom 'fair is foul	 and foul is fair '. Rent control legislation in Delhi	 as elsewhere in the country	 is broadly intended 'to provide for the control of rents and evictions and of rates of hotels and lodging houses and for the lease of vacant premises to Government	 in certain areas in the Union Territory of Delhi. This is understandable where the city population swells and the city accommodation stagnates	 the people suffocate for space and landlords 'make hay ' playing the game of 'each according to his ability to grab '. Parliament has built into the Act restriction on eviction. 14 (1) starts off: "Notwithstanding anything to the contrary in any other law or contract	 no order or decree for the recovery of posses 285 sion of any premises shall be made by any court or Controller in favour of the landlord against a tenant: Provided that the Controller may	 on an application made to him in the prescribed manner	 make an order for the recovery of possession of the premises on one or more of the following grounds only	 namely: . . . . . . . . The scheme of embargo on eviction makes a pragmatic swerve by the time we reach Sec. We can correctly visualise the scope and sweep of this provision only in its proper social setting. It carves out a category for special treatment. While no landlord can evict without compliance with Sections 14	 19 and 20; does a liberal eviction policy underlie Sec. 21 ? Apparently contrary but actually not once we understand the raison d 'etre of the section. Parliament was presumably keen on maximising accommodation available for letting	 realising the scarcity crises. One source of such spare accommodation which is usually shy is potentially vacant building or part thereof which the landlord is able to let out for a strictly limited period provided he has some credible assurance that when he needs he will get it back. If an officer is going on other assignment for a particular period	 or the owner has official quarters so that he can let out if he is confident that on his retirement he will be able to re occupy	 such accommodation may add to the total lease worthy houses. The problem is felt most for residential uses. But no one will part with possession because the lessee will become a statutory tenant and	 even if bona fide requirement is made out	 the litigative tiers are so many and the law 's delays so tantalising that no realist in his sense will trust the sweet promises of a tenant that he will return the building after the stipulated period. So the law has to make itself credit worthy. The long distance between institution of recovery proceedings and actual dispossession runs often into a decade or more a factor of despair which can be obviated only by a special procedure. Section 21 is the answer. The law seeks to persuade the owner of premises available for letting for a particular or limited period by giving him the special assurance that at the expiry of that period the appointed agency will place the landlord in vacant possession. As stated earlier	 the critical need was for residential	 not nonresidential housing. Therefore	 Section 21 confines this special remedy to letting for residential uses only. Parliament had the wholsome fear that if the section were not controlled by many conditions it might open the flood gates for wholesale circumvention of the rent control legislation by ingenious landlords exploiting the 286 agonising need of houseless denizens. Against this back drop	 let us read Section 21 and highlight the essential conditions written into the provision: "21. Where a landlord does not require the whole or any part of any premises for a particular period	 and the landlord	 after obtaining the permission of the Controller in the prescribed manner	 lets the whole of the premises or part thereof as resident for such period as may be agreed to in writing between the landlord and the tenant and the tenant does not	 on the expiry of the said period	 vacate such premises	 then	 notwithstanding anything contained in Section 14 or in any other law	 the Controller may	 on an application made to him in this behalf by the landlord within such time as may be prescribed	 place the landlord in vacant possession of the premises or part thereof by evicting the tenant and every other person who may be in occupation of such premises. " We must notice that Section 21 runs counter to the general scheme and	 therefore	 must be restricted severely to its narrow sphere. Secondly	 we must place accent on every condition which attracts the Section and if any one of them is absent the Section cannot apply and	 therefore	 cannot arm the landlord with a resistless eviction process. Thirdly	 we must realise that the whole effect of Section 14 can be subverted by ritualistic enforcement of the conditions of sanction under Sec. 21 or mechanical grant of sanction therein. Section 21 overrides Section 14 precisely because it is otherwise hedged in with drastic limitations and safeguards itself against landlords ' abuses. What	 then	 are those conditions and safeguards? The first condition is that the landlord does not require the demised premises "for a particular period" only. This means that he must indicate to the authority before which sanction is sought for letting what is the particular period for which he can spare the accommodation. The Controller must be satisfied that the landlord means what he says and it is not a case of his not requiring the property indefinitely as distinguished from a specific or particular limited period of say one year	 two years or five years. If a man has a house available for letting for an indefinite period and he so lets it	 even if he specifies as a pretense	 a period or term in the lease	 Section 21 cannot be attracted. On the other hand	 if he gives a special reason why he can let out only for a limited period and requires the building at the end of that period	 287 such as that he expects to retire by then or that he is going on a short assignment or on deputation and needs the house when be returns home it is good compliance. The second condition is that the letting must be made for a residential purpose. The house must be made over "as a residence". If it is let out for a commercial purpose	 Section 21 will not apply	 whether the ritual of a sanction under that provision has been gone through or not. Thirdly	 the Controller 's permission is obligatory where he specifies the particular period for which he gives permission and further qualifies the permission for use as a residence. The Controller exercises an important regulatory function on behalf of the community. The fact that a landlord and a potential tenant together apply	 setting out the formal ingredients of Section 21	 does not relieve the Controller from being vigilant to inquire and satisfy himself about the requisites of the landlord 's nonrequirement "for a particular period" and the letting itself being "as a residence". A fraud on the statute cannot be permitted especially because of the grave mischief that may be perpetrated in such event. It is easy to envisage the terrible blow to the rent control law if Section 21 were freely permitted to subvert the scheme of Section 14. Every landlord will insist ' on a tenant going through the formal exercise of Section 21	 making ideal averments in terms of that Section. The consequence will be that both the Civil Procedure Code which prescribes suits for recovery of possession and the Delhi Rent Control Act which prescribes grounds for eviction will be eclipsed by the pervasive operation of Section 21. Neither grounds for eviction nor suits for eviction will thereafter be needed	 and if the landlord moves the court for a mere warrant to place the landlord	 through the court process	 in vacant possession of the premises	 he gets it. No court fee	 no decree	 no execution petition	 no termination of tenancy wish for possession and the court is at your command. Such a horrendous situation will be the negation of the rule of law in this area. So it is that we deem it necessary to lay down the law as implied in Section 21 When an application under Section 21 is filed by the landlord and/or tenant	 the Controller must satisfy himself by such inquiry as he may make	 about the compulsive requirements of that provision. If he makes a mindless order	 the Court	 when challenged at the time of execution	 will go into the question as to whether the twin conditions for sanction have really been fulfilled. Of course	 there will be a presumption in favour of the sanction being regular	 but it will still be open to a party to make out his case that in fact and in truth the 288 conditions which make for a valid sanction were not present. We do not agree with the statement of the law by the Delhi High Court striking a contrary note. In this context	 we may make special reference to Kasturi Lal 's case	 a decision of the Delhi High Court reported in 1976 R.C.J.p. It is true as Misra	 J. in that case	 following earlier decisions has observed that the provisions of Section 21 are designed to meet the problem of shortage of housing in Delhi. If the landlord does not need the premises for a limited period	 section 21 permits him to lease it out during that period. Without the facility of section 21 the landlord might have preferred to keep the premises vacant	 but that does not mean that the law surrenders itself to this landlord and releases him from all conditions. That is why the need for sanction and the mandatory conditions for such sanction are specified in the section. It is altogether wrong to import the idea that the tenant having taken advantage of induction into the premises pursuant to the permission	 he cannot challenge the legality of the permission. As between unequals the law steps in and as against statutes there is no estoppel	 especially where collusion and fraud are made out and high purpose is involved. The doctrine of estoppel cannot be invoked to render valid a proceeding which the legislature has	 on grounds of public policy	 subjected to mandatory conditions which are shown to be absent: "Where a statute	 enacted for the benefit of a section of the public	 imposes a duty of a positive kind the person charged with the performance of the duty cannot by estoppel be prevented from exercising his statutory powers. A petitioner in a divorce suit cannot obtain relief simply because the respondent is estopped from denying the charges	 as the court has a statutory duty to inquire into the truth of a petition". It is an old maxim that estoppels are odious	 although considerable inroad into this maxim has been made by modern law. Even so	 "a judgment obtained by fraud or collusion	 even it seems a judgment of the House of Lords	 may be treated as a nullity." (See Halsbury 's Laws of England	 Vol. 16 fourth edition para 1553). The point is that the sanction granted under section 21	 if it has been procured by fraud or collusion	 cannot withstand invalidity because	 otherwise	 high public policy will be given as hostage to successful collusion. 289 Law that non performs stultifies the rule of law and so it is that we stress the need for strict compliance. Or else	 the sanction is non est. Collusion between the strong and the weak cannot confer validity where the mandatory prescriptions of the law are breached or betrayed. We have said enough to make the point that it is open to the tenant in the present case to plead and prove that the sanction under Section 21 is invalid	 and if it is void the executing court is not debarred from holding so. We	 therefore	 hold on the first point that no question of amendment arises in the present case and the application before the Controller did not suffer from any deficiency. On the second point we hold that it is perfectly open to the Controller to examine whether the sanction under Section 21 is a make believe	 vitiated by fraud and collusion. We make it clear that the Controller is concerned with delivery of possession at the expiry of the lease of 1975 and he will	 therefore	 examine the position with reference to that lease only. The appellant tenant urged a further contention that because there was fraud the court could not assist the party in fraud even if both sides were involved in the fraud. He invoked the doctrine of inpari delicto potior est conditio defendantis. We are not inclined to examine these contentions but leave it open to the executing court to go into such pleas as are permissible at the execution stage. Beyond that he has no jurisdiction but within that he has a duty to decide. On these findings we dismiss the appeal but direct the Controller to go into the question of the validity of the sanction and such other objections as may be available in the light of our observations recorded above. The first point raised is untenable and we should have directed costs while dismissing the appeal. The second point raised is of great public moment and the appellant has broadly succeeded on that question. The result is that the community has benefited by our declaration of the law and the parties must	 therefore bear their respective costs throughout. S.R. Appeal dismissed.

Dismissing the appeal by special leave	 the Court HELD: Section 21 of the Delhi Rent Control Act	 1958 carves out a category for special treatment. While no landlord can evict without compliance with sections 14	 19 and 20 of the Act	 a liberal eviction policy cannot be said to under lie in section 21. Parliament was presumably keen on maximising accommodation available for letting	 realising the scarcity crisis. One source of such spare accommodation which is usually shy is potentially vacant building or part thereof which the landlord is able to let out for a strictly limited period provided he has some credible assurance that when he needs he will get it back. The law seeks to persuade the owner of the premises available for letting for a particular period by giving him a special assurance that at the expiry of that period the appointed agency will place the landlord in vacant possession. And	 Section 21 confines the special remedy to letting for residential uses only. Parliament had the wholesome fear that if the section were not controlled by many conditions it might open the floodgates for wholesale circumvention of the rent control legislations by ingenious landlords exploiting the agonising need of houseless denizens. [285B D	 G H	 286A] 2. Section 21 over rides section 14 precisely because it is otherwise hedged in with drastic limitations and safeguards itself against landlords ' abuses. The first condition is that the landlord does not require the demised premises "for a particular period" only. This means that he must indicate to the authority before which sanction is sought for letting what is the particular period for which he can spare the accommodation. The Controller exercises an important regulatory function on behalf of the community. The fact that a landlord and a potential tenant together apply	 setting out the formal ingredients of Section 21	 does not relieve the Controller from being vigilant to inquire and satisfy himself about the requisites of the landlord 's non requirement "for a particular period" and the letting itself being "as a resident". A fraud on the statute cannot be permitted especially because of the grave mischief that may be perpetrated in such event. [286E	 H	 287A D] 3. There would be a terrible blow to the rent control law if section 21 were freely permitted to subvert the scheme of Section 14. Every landlord will insist on a tenant going through the formal exercise of Section 21	 making ideal averments in terms of that Section. The consequence will be that both the Civil Procedure Code which prescribes suits for recovery of possession and the Delhi Rent Control Act which prescribes grounds for eviction will be eclipsed by the pervasive operation of Section 21. Neither grounds for eviction nor suits for eviction will thereafter be needed	 and if the landlord moves the Court 282 for a mere warrant to place the landlord	 through the Court process	 in vacant possession of the premises	 he gets it. No court fee	 no decree	 no execution petition	 no termination of tenancy wish for possession and the court is at your command. Such a horrendous situation will be the negation of the rule of law in this area. [287 D F] 4. When an application under Section 21 is filed by the landlord and/or tenant the Controller must satisfy himself by such inquiry as he may make	 about the compulsive requirements of that provision. If he makes a mindless order	 the Court	 when challenged at the time of execution will go into the question as to whether the twin conditions for sanction have really been fulfilled. Of course	 there will be a presumption in favour of the sanction being regular	 but it will still be open to a party to make out his case that in fact and in truth the conditions which make for a valid sanction were not present. [287 G H	 288A] 5. The sanction granted under section 21	 if it has been procured by fraud and collusion cannot withstand invalidity because	 otherwise	 high public policy will be given as hostage to successful collusion. The doctrine of estoppel cannot be invoked to render valid a proceeding which the legislature has	 on grounds of public policy subjected to mandatory conditions which are shown to be absent. As between unequals the law steps in and as against statutes there is no estoppel	 especially where collusion and fraud are made out and high purpose is involved. [288D E	 G H] 6. Law that non performs stultifies the rule of law and hence the need for strict compliance. Or else	 the sanction is non est. Collusion between the strong and the weak cannot confer validity where the mandatory prescriptions of the law are breached or betrayed. [289A]