Pro-euro Labour MPs are warning that Britain risks returning to "boom and bust" if it does not join the single currency, as they launch a fresh campaign.

Father of the House of Commons Tam Dalyell has secured the backing of other senior party figures for his pro-euro pamphlet setting out the arguments in favour of British entry into the single currency.

The euro is not a 'distraction' from improving public services, it is vital to them

Tam Dalyell Labour MP

The new push closely follows the creation of a new Labour group fighting against the UK adopting the currency.

Downing Street has described as "pure speculation" a Sunday newspaper report that the decision on whether to hold a euro referendum could be brought forward to June this year.

Mr Dalyell's pamphlet, entitled Left Behind?, is being sent to every Labour MP in an effort to scotch claims the move would be bad for public services.

'Ending the doubts'

The veteran left-winger - the longest serving member of the Commons - says Labour's first term was about re-establishing that Britain could play a constructive role in Europe.

"In the second, we must finally put an end to the ambiguity that has dogged our country's relations with the European Union for the last 50 years," he said.

"Britain's public services have suffered from decades of under investment.

Peter Kilfoyle says pro-euro MPs face familiar foes

"In the past, plans for spending more on public services have been derailed by boom and bust."

Mr Dalyell suggests that cycle could return if Britain remains "isolated" outside the euro.

He meets head on the arguments of some of his fellow Labour backbenchers that joining the euro could distract from the core task of improving public services.

"Inside the euro, we would be free to give the public services the sustained investment that they so desperately need," he said.

"The euro is not a 'distraction' from improving public services, it is vital to them."

Arming the activists

Former Labour minister Peter Kilfoyle, who has written a letter that accompanies the pamphlet, told BBC Radio 4's Today programme: "I think the tests, however they are defined, can be met and it is a matter of what is the most judicious time to go for a referendum.

"What we are seeking to do is put the positive arguments in favour, so that when we do have a referendum, our people in the Labour Party are fully informed as to what the realities of the situation are.

"If we are going to have a reasonable debate, all of the arguments ought to be put. That is what we are trying to do."

Ian Davidson says the time is not right for a euro poll

Former deputy Labour leader Roy Hattersley also uses his foreword to the pamphlet to call for an early referendum.

Electoral 'hazard'

Earlier this month about 30 MPs and peers voiced their backing for the newly formed Labour Against The Euro (LATE).

The group warned Tony Blair that calling an early vote on issue could cost Labour more than 100 seats at the next general election.

LATE chairman Ian Davidson, said the economics for joining were currently "all wrong".

Most Labour voters see the euro as a distraction from the core business of improving public services, said Mr Davidson.

"At a time when Britain has high growth - the highest in Europe - low unemployment, low inflation, all the lowest in Europe, why do we want to go back to boom and bust and join the euro?"

Mr Davidson told Today that Britain did not want to become like France, where far-right politician Jean-Marie Le Pen has just won enough votes to take on Jacques Chirac to become the country's president.

"We have just heard the election results in France - discontent, economic discontent, leading to swings to the right. We don't want to join that," he said.

Early referendum?

Members of the group, which includes ex-ministers Frank Field and Lord Healey, argue that investment in public services would be restricted by the rules on euro membership.

The government says its economic assessment on joining will be complete by June next year.

But the Independent on Sunday says Tony Blair is ready for the test to be made as early as this June.

The newspaper says ministers do not want the campaign to become "mixed up" with the general election.

That decision would follow the political gamble taken with last week's tax rises to fund the NHS.

But the tax debate could dissuade Mr Blair from opening up another campaign so soon.