5.  The applicant was born in 1944 and lives in Ljubljana. 6.  For the relevant background to the case, see Ribać v. Slovenia (no. 57101/10, §§ 6-11, 5 December 2017). 7.  The applicant was a citizen of the Republic of Serbia in the Socialist Federal Republic of Yugoslavia (“the SFRY”). Following the dissolution of the SFRY, he retained citizenship of the then Federal Republic of Yugoslavia. He has had permanent resident status in Slovenia since 1977, where he also married and had two children. He was a member of the Yugoslav People’s Army (hereinafter “the YPA”). 8.  On 23 September 1991 he applied to the Vrhnika Military Post Office for early retirement as of 30 April 1992, and was then “available” (na razpolago) and on leave until his retirement. On 29 November 1991 the Office granted his request. 9.  On 25 October 1991 he left Slovenia with the YPA and went to Kraljevo. The applicant maintained that he had left with the YPA so he could fulfil the retirement conditions. On 21 December 1991 he returned to Slovenia, but left again in January 1992, which he maintained was for the purpose of arranging documents for his retirement. On 27 April 1992 the applicant returned to Slovenia, holding that it had not been possible for him to return earlier because of the war. 10.  On 16 July 1992 the military pension fund for the armed forces of the SFRY (hereinafter “the YPA Fund”) found the applicant to be entitled to an early retirement pension under SFRY military rules as from 1 May 1992. The applicant maintained that he had never received any pension from the YPA Fund. 11.  On 27 December 1991 the applicant applied for Slovenian citizenship under section 40 of the Citizenship Act (see paragraph 22 below). By a decision of 7 July 1992 the Ministry of the Interior refused his application, holding that the applicant had not lived in Slovenia between 25 October 1991 and 27 April 1992. The Supreme Court dismissed his subsequent appeal. 12.  On 29 July 1992 the applicant applied for an advance payment of his military pension under the Advance Payment of Military Pensions Ordinance (hereinafter “the Ordinance”; see paragraph 22 below). By a decision of 18 February 1993 the Pension and Disability Insurance Institute of Slovenia (hereinafter “the Institute”) refused the applicant’s application, finding that he had not fulfilled the conditions for pension entitlement under SFRY military rules, namely the age requirement, by 18 October 1991 (section 2(1)(2) of the Ordinance). The Institute also noted that the Ministry of Defence had opined that there had been no indication of the applicant having participated in aggression against Slovenia (section 2(2) of the Ordinance; see paragraph 22 below). His subsequent appeal was dismissed and the applicant initiated court proceedings. 13.  On 4 February 1994 the Court of Associated Labour of the Republic of Slovenia dismissed his claim, holding that the applicant had not fulfilled the conditions under section 2(1)(2) of the Ordinance (see paragraph 22 below) because he had not reached the required retirement age by 18 October 1991. The court emphasised that there had been nothing to suggest that the applicant had participated in aggression against Slovenia as a member of the YPA (section 2(2) of the Ordinance). An appeal, an appeal on points of law and a constitutional complaint all lodged by the applicant were dismissed. 14.  On 4 November 1998 the applicant applied for an old-age pension under the Act on the Rights Stemming from the Pension and Disability Insurance of Former Military Personnel (hereinafter “the 1998 Act”, see paragraph 22 below). On 25 February 1999 the Institute refused his application, holding that he had not continuously had permanent resident status in Slovenia between 25 June 1991 and October 1998 (section 2(1)(2) of the 1998 Act). The applicant appealed. 15.  On 12 August 1999 the Institute dismissed the appeal, holding that the applicant had not fulfilled the statutory requirements under the 1998 Act because he had not continuously had permanent resident status in Slovenia for the relevant period and had failed to claim his pension rights by 25 June 1991 (section 2(1)(2) of the 1998 Act). 16.  On 10 January 2003 the Ljubljana Labour and Social Court dismissed an application for judicial review lodged by the applicant. It pointed out that the applicant had fulfilled the permanent resident status requirement, but had nevertheless not claimed his pension rights by 25 June 1991. 17.  Meanwhile, in October 1999 the applicant reapplied for Slovenian citizenship. On 15 May 2002 the Ministry of Interior issued an assurance to the applicant that he would be granted citizenship if he could prove that he had been released from his current citizenship. On 2 December 2002 the applicant asked the Ministry to grant him citizenship on the basis of the amended Citizenship Act without prior release from his current citizenship. On 4 February 2003 the applicant acquired citizenship by naturalisation under section 19 of the amended Citizenship Act (see paragraph 22 below). 18.  On 19 May 2003, after lodging a new request with the Institute, the applicant was granted an old-age pension as from 4 February 2003 under the Pension and Disability Insurance Act (hereinafter “the general rules”). 19.  The applicant appealed, arguing that he should have been granted the pension as from 1 May 1992. On 3 November 2003 the Institute dismissed his appeal, holding that the applicant had been entitled to an old-age pension under the general rules and section 2(4) of the 1998 Act as from 4 February 2003 – when he had acquired Slovenian citizenship. An application that he lodged for judicial review and a subsequent appeal were also dismissed by the Ljubljana Labour and Social Court and the Higher Labour and Social Court respectively, reiterating the Institute’s arguments. 20.  On 23 March 2009 the Supreme Court dismissed an appeal on points of law lodged by the applicant. The court reiterated that under new section 15 of the 1998 Act (see paragraph 23 below), the applicant would be entitled to a pension retroactively only if he had acquired citizenship under section 40 of the Citizenship Act. 21.  On 30 March 2010 the Constitutional Court refused to accept for consideration a constitutional complaint lodged by the applicant, finding that it did not concern an important constitutional issue or entail a violation of human rights which had serious consequences for him.