A Fianna Fáil party political broadcast shown Wednesday night features outgoing British Prime Minister Tony Blair, former US president Bill Clinton and negotiator George Mitchell praising Taoiseach Bertie Ahern's role in the peace process.
The four-minute film was first shown to journalists after the party's daily press conference this morning.
According to Fianna Fáil, the three individuals knew they were participating in a party political broadcast and approved the film.
A Labour spokesperson said Mr Clinton and Mr Mitchell are both out of office and Mr Blair is about to go out of office and are quite free to pay tribute to whoever they wish.
The party said the Labour Party and the majority of voters are now looking to the future, not to the past.
Fine Gael leader Enda Kenny said Fianna Fáil was entitled to use any figureheads or personalities it wants in its party political broadcasts.
But Mr Kenny said people are not going to judge former US President Clinton, British Prime Minister Blair or former US Democratic Party Senator Mitchell on polling day.
Fianna Fáil has rejected Opposition criticism, and speaking on RTÉ Radio, Martin Cullen said the Taoiseach had achieved much for Ireland and that their successful policies were transforming people's lives.
The Taoiseach said it was a powerful broadcast and he pointed out that Angela Merkel had earlier lent her support to Fine Gael.