THE MERE FAILURE BY A NATIONAL OF A MEMBER STATE TO COMPLY WITH THE FORMALITIES CONCERNING THE ENTRY , MOVEMENT AND RESIDENCE OF ALIENS IS NOT OF SUCH A NATURE AS TO CONSTITUTE IN ITSELF CONDUCT THREATENING PUBLIC POLICY AND PUBLIC SECURITY AND CANNOT THEREFORE , BY ITSELF , JUSTIFY A MEASURE ORDERING EXPULSION OR TEMPORARY IMPRISONMENT FOR THAT PURPOSE .
4 . A DECISION ORDERING EXPULSION CANNOT BE EXECUTED , SAVE IN CASES OF URGENCY WHICH HAVE BEEN PROPERLY JUSTIFIED , AGAINST A PERSON PROTECTED BY COMMUNITY LAW UNTIL THE PARTY CONCERNED HAS BEEN ABLE TO EXHAUST THE REMEDIES GUARANTEED BY ARTICLES 8 AND 9 OF DIRECTIVE NO 64/221 .
5 . ARTICLES 53 AND 62 OF THE TREATY PROHIBIT THE INTRODUCTION BY A MEMBER STATE OF NEW RESTRICTIONS ON THE ESTABLISHMENT OF NATIONALS OF OTHER MEMBER STATES AND THE FREEDOM TO PROVIDE SERVICES WHICH HAS IN FACT BEEN ATTAINED AND PREVENT THE MEMBER STATES FROM REVERTING TO LESS LIBERAL PROVISIONS OR PRACTICES IN SO FAR AS THE LIBERALIZATION MEASURES ALREADY ADOPTED CONSTITUTE THE IMPLEMENTATION OF OBLIGATIONS ARISING FROM THE PROVISIONS AND OBJECTIVES OF THE TREATY .
6 . THE FREEDOM LEFT TO THE MEMBER STATES BY ARTICLE 189 AS TO THE CHOICE OF FORMS AND METHODS OF IMPLEMENTATION OF DIRECTIVES DOES NOT AFFECT THEIR OBLIGATION TO CHOOSE THE MOST APPROPRIATE FORMS AND METHODS TO ENSURE THE EFFECTIVENESS OF THE DIRECTIVES .