Divisions within the Labour Party over Tánaiste Eamon Gilmore's leadership have emerged after substitute MEP Phil Prendergast called for his resignation.

Ms Prendergast's intervention has also raised questions about the stance of deputy leader Joan Burton, Minister for Social Protection. Ms Prendergast also said Ms Burton should lead the party.

Even as Ms Burton said she supported Mr Gilmore, she described Ms Prendergast as a person “of substance”, leading to criticism from some of her senior Labour colleagues.

One Labour Minister said he urged Tánaiste Eamon Gilmore to tell Ms Burton to "put up or shut up" and declare her full support for him.

The Minister told The Irish Times that Mr Gilmore would have to tackle Ms Burton after comments she made about Ms Prendergast, who has called on the Tánaiste to resign.

However, Mr Gilmore’s official spokeswoman said last night no such conversation had taken place. Ms Burton described Ms Prendergast as a person “of substance” but said she supports the Tánaiste. “Eamon Gilmore is the leader of the Labour Party, he has my support in that and there is no leadership question.”

The Minister said of Ms Burton: “If I were Eamon Gilmore I’d be calling her in and having that chat with her. She needs to put up or shut up now, fully back him or challenge him.”

Questions over Mr Gilmore’s leadership have raised concern about a potential threat to the stability of the Coalition after the elections.

High-level figures in Fine Gael say Labour should not allow itself to become distracted from the Government's prime task of repairing the economy.

At the same time, Ms Prendergast’s intervention has brought into the open divisions within Labour over Mr Gilmore’s leadership.

While some TDs warned the matter would have to be debated if Labour fares very badly next month, others said the incident may yet galvanise the party behind the Tánaiste and make a leadership challenge less likely. “If you want to change a leader you have to ask who is the alternative, and is there somebody better?” asked one TD. “And in my view there isn’t.”

Still other party figures said it was already clear that Mr Gilmore’s position is on the agenda and the matter should be confronted after the election. “There’s a feeling that this issue will have to be addressed after the election,” said a senior TD.

“There’s a feeling that this election will tell a story, not just in relation to the leader, but also in relation to what we are at in Government. There’s no appetite for blowing this thing open essentially in the middle of an election campaign.”

Carlow-Kilkenny TD Ann Phelan, who is close to Ms Prendergast, acknowledged questions over the leadership.

“We’ve been sliding down in the polls. If we do badly in the elections, there will be questions about the leadership.

“That’s what leadership is about. I will go into the election with Eamon as leader, but if we do badly, then we have to face reality.”

Mr Gilmore himself brushed off Ms Prendergast’s attack, insisting he was “relaxed about it” and saying he still backs her campaign. “I support her, the party supports her in her effort to be re-elected.”

Asked about the situation in Labour, Taoiseach Enda Kenny mounted an uncompromising defence of the party’s performance and said the Government will serve its full term.

“I commend the Labour Party for the way they have stuck to the plan and the agenda of sorting out our public finances,” said Mr Kenny.