5.  The facts of the case, as submitted by the parties, may be summarised as follows. 6.  The applicant was born in 1955 and lives in Mielec. 7.  The applicant is married and has four children born in 1982, 1984, 1986 and 1994. Prior to his application for an early-retirement pension he had been unemployed with no right to unemployment benefit. 8.  On 31 May 2001 the applicant filed an application with the Rzeszów Social Security Board (Zakład Ubezpieczeń Społecznych) to be granted the right to an early-retirement pension for persons raising children who, due to the seriousness of their health condition, required constant care, the so‑called “EWK” pension. 9.  Along with his application for a pension, the applicant submitted, among other documents concerning his daughter’s health condition, a medical certificate issued by a specialist medical centre. The certificate stated that the child (born in 1994) suffered from chronic asthma and that she was in need of her parent’s constant care. 10.  On 31 July 2001 the Rzeszów Social Security Board (“the SSB”) issued a decision granting the applicant the right to an early‑retirement pension in the net amount of 870.83 Polish zlotys (PLN). The pension was granted with retroactive effect of 1 May 2001. 11.  On an unknown date the Rzeszów Social Security Board asked the Main Social Security Board’s doctor (Główny Lekarz Orzecznik) to inform it whether the applicant’s daughter required the permanent care of a parent. The doctor stated that, on the basis of the medical documents, the child could not be considered as ever having required such care. 12.  On 18 July 2002 the Rzeszów Social Security Board reopened the pension proceedings and, on 8 August 2002, the Board refused the applicant the right to early retirement and discontinued the payment of the pension with effect of 1 August 2002. 13.  The applicant appealed against the decision divesting him of the right to an early-retirement pension. He submitted that he should receive the benefit because his child required constant care, as confirmed by the medical certificate attached to the applicant’s original application for a pension. Moreover, the applicant alleged that the revocation of his retirement pension was contrary to the principle of vested rights. 14.  On 24 October 2003 the Tarnobrzeg Regional Court (Sąd Okręgowy) amended the challenged decisions and granted the applicant the right to early retirement pension with effect of 1 August 2002. The Regional Court found that the applicant could not bear the responsibility for the mistake made by the administrative authorities. It further held that the pension proceedings could not be reopened in this case because no new circumstances had arisen; the reopening decision was based on the same circumstances freshly assessed. 15.  The Rzeszów Social Security Board appealed against the first‑instance judgment. 16.  On 17 March 2004 the Rzeszów Court of Appeal (Sąd Apelacyjny) amended the first-instance judgment and dismissed the applicant’s appeal against the Social Security Board’s decisions. It held, among other things, that the Social Security Board based its decisions on evidence which did not constitute basis for the original decision granting the applicant the early retirement pension, namely medical documentation concerning the applicant’s daughter. 17.  On 22 June 2004 the Supreme Court (Sąd Najwyższy) refused to entertain the cassation appeal lodged by the applicant’s lawyer. 18.  Following the social security proceedings the applicant was not ordered to return his early-retirement benefits paid by the Social Security Board, despite the revocation of his right to an early-retirement pension. 19.  The Government submitted that after the revocation of the applicant’s pension, he was employed between 6 and 8 August 2002, between 2 October and 31 December 2002, 19 January and 31 May 2003, 10 August and 10 October 2003, 3 November and 31 December 2003, 13 January and 6 November 2004, 30 July and 4 August 2005, 19 and 23 June 2006, 30 July and 8 December 2008. According to the Government’s submissions the applicant was receiving an unemployment benefit for one year between January 2005 and January 2006 and, subsequently for 3 months in 2009. 20.  The Government further submitted that the applicant’s income represented some 12.11% of the average remuneration in Poland in 2002 27.99% in 2003, 29.09% in 2004, 21.91% in 2005, 18.88% in 2006, 30.25% in 2007, 33.02% in 2008, 15.09% in 2009 and 52.54% in 2010. 21.  The applicant submitted a document issued by the Social Security Board on 17 August 2009 confirming that his early-retirement pension had been revoked with effect of 2 August 2002 and that after that date he had not received any payments from his retirement or disability insurance. 22.  The applicant further submitted copies of the Social Security Board’s decisions according to which he was receiving monthly family benefit for his four children. The benefit amounted to PLN 135.96 in August 2001, PLN 469.02 in October 2001, PLN 409 in June 2002 and PLN 333.06 in October 2002. The applicant further produced a certificate issued by the Social Care Centre on 18 August 2008, according to which the applicant’s family was receiving a social care benefit between 1 May 2004 and 31 August 2007. After the latter date the social care centre did not pay the applicant any further benefits. The certificate did not specify the amount of benefit granted.