Former Fianna Fáil minister Michael Woods stands to gain about €75,000 in backdated pension payments through a special provision in a Bill which goes before the Seanad today.
However, last night Fine Gael pointed out that the country's old age pensioners were prohibited from benefiting from similar backdating arrangements.
The Department of Finance confirmed yesterday that a special provision had been inserted into legislation passed by the Dáil last week to enable a back payment to be made to Mr Woods.
The change will allow a minister who has failed to claim his or her pension within the specified time period of six months to receive back pay from the time they make the claim.
Mr Woods said the anomaly had come to light when he discovered that his ministerial pension could not be backdated because he had neglected to apply for it in writing when his normal severance payments ended.
However, Mr Woods denied that he had lobbied for the change in the law to enable him to claim the back payment.
"I actually applied for the pension, but I did so at the time when I applied for my severance payment. I thought that once you did that, that would cover the pension application, but I now realise that I should have put in an application when the severance payment ended," he said.
Under the ministerial pensions system ex-ministers get severance payments for two years and are then entitled to a pension equal to 50 per cent of their ministerial salary if they are aged 50 or over. They only get half of this figure while they remain as TDs.
"I discovered myself after a year and a bit that I wasn't being paid the pension, and that I wasn't getting anything. I had thought that I had gone into the pension scheme," said Mr Woods. He said that he went into the pensions section in Finance and ultimately the problem was referred up to the Minister.
"I got a letter from the Minister in April this year to say that he was aware of the problem. I did not approach the Minister.
"I'm not particularly happy about my pension payments being on the front page of papers, but you get used to it. It isn't pleasant. It isn't actually a very big pension. It's worth €37,000 now," said Mr Woods.
Fine Gael spokesman for Older People Paul Connaughton said State pensioners can only get their pensions backdated for a maximum of six months.
"The Fianna Fáil Government has legislated to allow one individual get extra back pay. Will all others in the same boat now be extended the same courtesy?" asked Mr Connaughton.
"When acting on behalf of constituents who, like the former minister, neglected to apply for their pension in time, I was told that ignorance of the rules is no excuse and only a maximum of six months' pension entitlements will be granted," he said.
"Brian Cowen is clearly looking out for a former colleague and friend, all State pensioners now have the right to know whether he will look out for them too," said Mr Connaughton.
Mr Woods, who will be 72 in December, served as a cabinet minister for 14 years, more than the nine years required for a maximum ministerial pension. He was dropped from the cabinet in 2002 and was in receipt of severance payments for two years after that on top of his Dáil salary.
Mr Woods now has a salary of €101,446 a year as a TD, plus €20,000 as a committee chair. He also qualifies for half of the ministerial pension of €37,000 or so at present and will get the full amount when he retires as a TD.