LUCINDA Creighton was embroiled in a sparring match with Eamon Gilmore over the Tanaiste's efforts to ensure Ireland's corporation tax rate is taken off the table.
Ms Creighton said the Labour Party leader needed to do more to get his sister party in Germany to back off on demands to increase Ireland's corporation tax.
She says Mr Gilmore and Labour have to "call on their comrades to show solidarity".
However, the Tanaiste's officials say Mr Gilmore is lobbying hard on that front and Ms Creighton is "out of the loop" following her resignation as a junior minister.
But the Dublin South-East TD said she was concerned about noises coming from the German socialists about Ireland's corporate tax rate featuring in the coalition government negotiations.
Ms Creighton said Fine Gael has been ensuring centre-right leaders were aware of Ireland's position.
"I think it's important the Labour Party, as a partner in Government, does the same with its political partners right across Europe, particularly in Germany, where we are hearing very worrying noises about corporation tax, specifically Irish corporation tax and about the direct recap of the banks.
"I don't think the leadership of the Labour Party can afford to stay silent," he said.
Mr Gilmore's spokesman said the Tanaiste "has been and will be" in contact with officials in the SPD, who are involved in coalition talks with Chancellor Merkel's CDU.
As recently as this week, he spoke with his German counterparts and has another call with a senior official scheduled for next week.
"If she was still a minister, she would understand these types of things were happening. It more signifies that she's out of the loop," the spokesman said.
Ms Creighton was attending the EPP meeting in her capacity as a vice-president of the group.
Her expulsion from the parliamentary party after voting against abortion legislation has not affected her elected EPP position.