5.  The applicant was born in 1942 and lives in Maribor. 6.  The Socialist Federal Republic of Yugoslavia (“the SFRY”) was a federal State composed of six republics: Bosnia and Herzegovina, Croatia, Serbia, Slovenia, Montenegro and Macedonia. Nationals of the SFRY had “dual citizenship” for internal purposes, that is to say they were citizens of both the SFRY and one of the six republics. They had freedom of movement within the federal State and could register as permanent residents wherever they settled on its territory. 7.  The SFRY had two pension systems – military and civil. The pension rights of military personnel were regulated by and secured through the federal authorities. In particular, members of the Yugoslav People’s Army (hereinafter “the YPA”), the armed forces of the SFRY, paid their contributions to and received their pensions from a special military pension fund based in Belgrade (Zavod za socialno osiguranje vojnih osiguranika, hereinafter “the YPA Fund”). The YPA Fund paid pensions to military pensioners irrespective of where they undertook military service or lived once retired. This was the only pension fund existing at federal level. In parallel, each republic had in place its own pension legislation and public pension fund set up for the payment of civil pensions. 8.   Between 1991 and 1992 the SFRY broke up. On 25 June 1991 Slovenia declared its independence. 9.  In 1992 the Slovenian Government issued the Ordinance on the payment of advances on military pensions (see paragraph 28 below, hereinafter “the Ordinance”) which regulated, on a temporary basis, the payment of military pensions to former YPA military personnel residing in the Republic of Slovenia who had applied for or fulfilled the conditions for retirement under the rules governing the pension and disability insurance of military personnel (hereinafter “the SFRY military rules”) by 18 October 1991, the date of withdrawal of the YPA from Slovenia (see P.P. v. Slovenia, no. 39923/98, Commission decision of 1 July 1998, Decisions and Reports (DR) 3, p. 25). This was followed in 1998 by a new Act on the Rights Stemming from the Pension and Disability Insurance of Former Military Personnel (see paragraph 29 below, hereinafter “the 1998 Act”) which put in place a comprehensive regulatory framework for the pension rights of former YPA military personnel, in most cases allowing for pensions to be paid only to Slovenian nationals. 10. In 1994 the Federal Republic of Yugoslavia (succeeded in 2006 by Serbia) transformed the YPA Fund (see paragraph 7 above) into the Social Insurance Fund of Military Personnel of the Federal Republic of Yugoslavia on the basis of the Yugoslav Army Act. The (transformed) YPA Fund continued paying YPA pensions to the citizens of the Federal Republic of Yugoslavia. However, it remains uncertain to what extent, if at all, the YPA Fund continued paying YPA pensions to the citizens of the Federal Republic of Yugoslavia residing in the other former SFRY republics (see also, mutatis mutandis, Kudumija v. Bosnia and Herzegovina and Serbia, and Remenović and Mašović v. Bosnia and Herzegovina, (dec.), nos. 28233/08 and 2 others, § 11, 4 June 2013). 11.  At the inter-State level, however, the question of responsibility for the payment of pensions to military personnel who had acquired or applied for pensions with the YPA Fund under the rules governing the pension and disability insurance of military personnel (hereinafter “the SFRY military rules”) remained unresolved until the Agreement on Succession Issues entered into force in 2004 (see paragraph 30 below). 12.  The applicant was a citizen of the Republic of Serbia in the SFRY. Following its dissolution, he retained citizenship of the then Federal Republic of Yugoslavia. He has been residing in Slovenia since 1964 and has had permanent resident status since 1981. In 1969 he married a Slovenian woman, with whom he had two children. He was a non-commissioned officer in active military service in the YPA until 30 September 1991, when he retired. 13.  On 16 July 1991 he applied for retirement to the Maribor military district headquarters, and was then “available” (na razpolago) until his retirement. On 13 November 1991 the YPA Fund found him to be entitled to an old-age pension under the SFRY military rules as from 1 October 1991 with more than forty-one pensionable years with bonus (benificirana doba) in the YPA. The applicant maintained that he had only received his pension from the YPA Fund twice (in November 1991 and January 1992), when he had personally gone to Belgrade to collect it. 14.  On 23 October 1991 the applicant applied for Slovenian citizenship under section 40 of the Citizenship Act (see paragraph 26 below). By a decision of 11 July 1992 the Ministry of Interior dismissed his application. It based its decision on section 40(3) and section 10(1)(8) of the Citizenship Act, which stipulated that the Ministry was allowed to refuse an application where there was reason to believe that the person posed a threat to public order, security or national defence. After the Constitutional Court quashed the decision and the case was remitted to the Ministry of Interior for fresh consideration, the latter on 2 September 1997 again dismissed his application on the same grounds. The applicant instituted court proceedings, which were unsuccessful. On 13 October 2005 the Constitutional Court rejected a constitutional complaint by him on the grounds that it was no longer relevant because he had acquired Slovenian citizenship in 2003 (see paragraph 19 below). 15.  On 27 February 1992 the applicant applied for an advance on his military pension under the Ordinance (see paragraph 28 below). On 29 April 1993 he requested the YPA Fund to discontinue the payment of his pension. By a decision of 17 May 1993 his payments were stopped with effect from 31 January 1992. The applicant lodged this request after realising that the Pension and Disability Insurance Institute of Slovenia (hereinafter “the Institute”) only granted advances under the Ordinance provided that the YPA Fund stopped paying the pension. By a decision of 5 May 1993 the Institute found that the applicant had been entitled to such an advance starting from 1 November 1991. It held that he had been a permanent resident of Slovenia since 1 April 1981 and had fulfilled the conditions for pension entitlement under the SFRY military rules by 18 October 1991. 16.  On 13 October 1998 the Institute, on the basis of section 25 of the 1998 Act (see paragraph 29 below), issued of its own motion a decision not to convert the applicant’s advance on his military pension into an old-age pension under the 1998 Act. His advance was suspended as of 31 October 1998. The Institute decided that since the applicant had been in active military service in the YPA from 25 June to 18 July 1991 and from 18 July 1991 had been on leave, he did not fulfil the statutory conditions for converting the advance on his military old-age pension into an old-age pension under section 2(1)(4) of the 1998 Act. 17.  The applicant appealed, complaining that at the relevant time he had not been on leave, but had been available until his retirement. On 30 September 2002 the Institute dismissed his appeal, holding that he could not be considered a beneficiary under section 2(1) of the 1998 Act as he did not have Slovenian citizenship and did not comply with the requirements applicable to foreign beneficiaries. It added that he could re-apply for an old-age pension under the 1998 Act once he acquired Slovenian citizenship. 18.  The applicant subsequently applied for judicial review of the Institute’s decision before the Ljubljana Labour and Social Court, maintaining that, as a resident of Slovenia, he should have been treated in the same way as Slovenian citizens. 19.  On 1 April 2003 the applicant acquired citizenship by naturalisation under section 19 of the amended Citizenship Act read in conjunction with section 10(1) of the Citizenship Act (see paragraph 27 below). 20.  On 4 June 2003, after lodging a new request with the Institute, the applicant was granted an old-age pension as from 1 April 2003. 21.  On 13 January 2006 the Ljubljana Labour and Social Court dismissed the application for judicial review (see paragraph 18 above). It pointed out that the applicant’s situation had to be assessed with regard to the different categories of beneficiaries listed in section 2(1) of the 1998 Act. It concluded that the applicant had not fulfilled the conditions for an old-age pension set out in section 2(1)(2) of the 1998 Act. Likewise, as a foreigner he had not met the conditions set out in section 2(1)(4) of the 1998 Act. He had therefore been eligible for an old-age pension under section 2 of the 1998 Act only from 1 April 2003 onwards, the date on which he had acquired Slovenian citizenship. 22.  The applicant lodged an appeal with the Higher Labour and Social Court. On 21 March 2007 the appeal was dismissed, essentially on the grounds that in the legally relevant period the applicant had been a foreigner who had not had rights to a pension or other benefits under the SFRY military rules by 25 June 1991 as required by section 2(1)(2) of the 1998 Act. The court held that the other provisions of section 2 of the 1998 Act were applicable only to Slovenian citizens and, thus, the applicant, who had not fulfilled the condition of nationality, should not have relied upon them. 23.  The applicant lodged an appeal on points of law, claiming he should have been treated the same as Slovenian citizens. On 23 March 2009 it was dismissed by the Supreme Court, which followed the lower courts’ reasoning. It held that in the period at issue the applicant had not met the requirements of any of the categories of beneficiaries under section 2 of the 1998 Act, having applied for the pension under the SFRY military rules on 16 July 1991 and having only acquired Slovenian citizenship on 1 April 2003. 24.  On 24 March 2010 the Constitutional Court decided not to accept a constitutional complaint by the applicant for consideration, finding that it did not concern an important constitutional issue or entail a violation of human rights which had serious consequences for him.