Union leaders have been meeting to discuss the aims of a possible third term for the Labour government.

Amicus general secretary Derek Simpson, Unison chief Dave Prentis and head of the GMB union Kevin Curran were among those participating in the event organised by the Catalyst think tank.

The meeting came as questions remained over Tony Blair's leadership.

Tony Woodley, the TGWU general secretary who has in the past called for the prime minister to resign, chaired the discussions.

"The trade unions played a central and invaluable role in securing Labour's general election victories in 1997 and 2001 - not only through their financial contributions, but by their provision of campaign and election workers, their mobilisation activities and volunteers, and their policymaking input," said Catalyst director Martin McIvor.

"At a time of low voter turnout and widespread disconnection from the political process, trade unions constitute a vital link between national party politicians and voters and communities on the ground.

"This seminar is about ensuring that they work closely with each other and with the party over the coming period to help bring about another election victory for progressive policies which reflect the needs of working people."

Speaking on Monday's BBC Newsnight programme, Curran argued that the meeting represented a "watershed" in the Labour Party's history.

"That is how important it is and the government have got to start listening now," he said.

"We are not saying to the government, here is a shopping list, we are saying look you need to start reflecting the values and expectations of our members.

"And if we don't have a radical third term my very strong view is there will be a rift...us, the trade union movement, looking for another political vehicle to advance our members social and economic agenda.

"I don't think we will get that far but I have got to be clear in my analysis on behalf of the GMB membership that we could go down that route unless we get a radical third term."

Leadership row

Speaking on the BBC Radio 4 Today programme, Amicus chief Simpson insisted that more work is needed to put British workers on a par with their European counterparts.

"Employment rights in the UK don't reach the levels of our colleagues in Europe and we can't understand why we don't enjoy the same rights as they do in France, Germany or Italy and so on," he said.

However, he insisted that the conflict between the Labour Party and the unions was not over leadership.

"I am less concerned about the individual who is in the prime minister's job than I am about the policies that the government is pursuing," he said.

"What we are trying to do is point out some of the realities - that if you want to keep a core Labour support, you have to address some questions somewhat differently than we have been able to address them so far.

"That is not the purpose here - it is not an attack on the government and it is not an attack on Tony Blair or Gordon Brown.

"It is a very concern that [on] these issues people find it difficult to understand why we are not addressing them in a more direct method.

"People do, of course, pay very great credit to what has been done already.  It is the fact that more needs to be done that will engage the interest and support.

"The government itself recognises some of its core support is perhaps not as enthusiastic as it might be."

The meeting came after Labour's former deputy leader Lord Hattersley called for the unions to stand up to the prime minister.

"It should have happened years ago. A battle over the two-tier workforce in the public sector, PFI, top-up fees, foundation hospitals, selective secondary education or, above all, Iraq would have done the government immense temporary damage," he wrote in Monday's Guardian.

"And it would have stopped future folly dead in its tracks. The strategy for this October's Labour conference ought to be built on a simple ultimatum.

"Tony Blair should be forced to choose between speaking for the party, rather than himself, and facing a surge of conference decisions that would make his position untenable.

"The argument is not about him. It is about Labour. The time has come for Labour to win."