Brian Cowen and Bertie Ahern are to have more than €1,600 a year added to their six-figure pensions.
The Sunday Times says the windfall is thanks to a side deal to the Landsdowne Road agreement on public sector pay.
The two former Taoisigh currently get around €134,000 per year, but last month's pact will see that figure rise to almost €136,000.
A number of other former ministers and Taoisigh with pensions above €100,000 will also receive a maximum increase of €1,680.
Renua party leader, Lucinda Creighton, says taxpayers will find the increases particularly difficult in a week where the Banking Inquiry showed the 'serial ineptitude of our leaders'.
She told the newspaper that, "this is like something out of Kafka. Brendan Howlin has lost touch with reality if he thinks the public will accept rewarding failure".
Brian Cowen told the Banking Inquiry earlier this week that "the primary responsibility of the crisis rests with the banks themselves", but added he takes full and complete responsibility for his role in and response to the economic crisis.
