Former Cabinet minister Lord Mandelson has urged Labour not to promise a referendum on the EU, warning it would "split the party from top to toe".
With David Cameron suggesting that he will offer voters a chance after the general election to express their "fresh consent" for a new settlement of the UK's relations with the EU, speculation is growing that Labour may seek to steal a march on the Prime Minister by promising a referendum.
But Lord Mandelson, a former European commissioner, said that Labour would be unable to campaign in a united way in a national vote on Europe.
Asked if he thought his party's leader Ed Miliband should offer a referendum if the Tories do so, Lord Mandelson said: "No I don't. First of all, it's not justified in the national interest. Secondly, the idea that it would 'clear the air' as I have heard one of two people in my party suggesting... It would, I think, do the opposite.
"It would split the Labour Party from top to toe. We wouldn't be able, I don't think, to campaign in a united way.
"On what? On a trifling proposition which has almost nothing to do with real or profound change that is taking place in Europe but is simply being created to satisfy the demands of those who want to 'clear the air'. I think it would do exactly the opposite."
Lord Mandelson questioned whether Mr Cameron personally wants a referendum, and said the Prime Minister was raising "dangerous" expectations among his activists and backbenchers.
"He is raising the stakes and creating expectations which he will not be able to deliver, and I think that is very dangerous for him," said Lord Mandelson. "My view of David Cameron is that if he could bury the whole subject of Europe he would... He doesn't want to divide his party in that way.
"But he is throwing red meat to his backbenchers who are looking for blood and it's European blood that they want - partly because they are puritans and dogmatists as far as Europe is concerned but secondly because they are scared rigid of Ukip."
Lord Mandelson added: "What we have seriously got to do as a country is look to the long term, establish what our real interests are as a country, realise that we are European and there is nothing anyone can do about that and that our force, our influence, our clout and our ability to project both our interests and our values in the world are better served by remaining a member of the European Union. That in my view should be our starting point."