Fianna Fáil and the Green Party questioned Sinn Féin's track record in separate statements this weekend.
Fianna Fáil attacked the party's European candidate in Dublin, Ms Mary Lou McDonald, over her appearance last year at a commemoration for the Nazi collaborator and former IRA leader, Mr Seán Russell.
The Greens, meanwhile, accused Sinn Féin of inconsistency over its opposition to the Irish visit of President Bush, some 14 months after party president, Mr Gerry Adams, met Mr Bush at the Hillsborough summit.
Both attacks were rejected by Sinn Féin as "signs of desperation".
Fianna Fáil European election candidate in Dublin, Mr Eoin Ryan TD, said Ms McDonald had shared a platform at the Seán Russell commemoration with the senior IRA figure, Mr Brian Keenan, who served a prison sentence in England for explosives offences.
"The people of Dublin and Ireland should know the kind of company Mary Lou McDonald keeps. And what of the person McDonald and Keenan gathered together to 'pay respect' to - Seán Russell, a self-proclaimed ally of Hitler, Nazi Germany and former leader of the IRA."
A Sinn Féin spokesman responded: "I think Eoin Ryan should look at his own party's history before starting to throw around accusations ... considering Eamon de Valera signed a book of condolences on the death of Adolf Hitler."
