EU-Turn? What EU-Turn?

First returned at a by-election in 1982, Harriet Harman is the Mother of the House. Dame Margaret Beckett was first elected in 1974, but her service has not been continuous, although it has been since 1983. The inevitable Dame Harriet goes back so far that pronounced hostility to the EU was the only way to get on in the Labour Party.

But then, it was Labour that kept Britain out of the euro, accession to which would certainly have followed a Conservative victory in 1997, when Ken Clarke would have remained Chancellor of the Exchequer. The 1997 General Election was Britain's referendum on the euro, and the right side won.

At or around the core of the New Labour project were numerous figures who had never become any friends of the EU: Harman, Beckett, John Prescott, Gordon Brown, Robin Cook, Jack Straw, David Blunkett, Peter Hain (who had voted against Maastricht and whom Blair appointed as Europe Minister), Tessa Jowell (whom certain newspapers had misreported as among the third of Labour MPs who had defied a three-line whip to abstain and voted against Maastricht, such was the expectation that she would do so), the Oxbridge-Australian Brahmin that was Patricia Hewitt, Alastair Campbell, Ed Balls, Jon Cruddas, Geoffrey Robinson, and many more besides.

Blair himself just used to ignore the EU whenever it suited him, and it suited him quite a lot of the time.

The General Secretaries of Unite and the GMB have been calling for a referendum on EU membership for a matter of years, and the single largest individual donor to the Labour Party is John Mills, whose views have never changed since he was Secretary of the No Campaign in 1975.

This year's Labour manifesto promised a referendum under certain circumstances, merely different ones from those which David Cameron pretended to envisage while assuming that the whole notion would disappear in coalition negotiations with the Lib Dems.

What matters now is the referendum question. That still needs to be on, and not in anticipation of, Cameron's renegotiation. His authority for that is his General Election victory, before which he promised a referendum on the eventual deal in all its specifics. That is what there needs to be, if there is going to be a referendum at all.

But it is impossible to see how any such deal could be acceptable to any other party in the House of Commons apart from the two Ulster Unionists, and difficult to see how even they could be persuaded to support Cameron against the opponents in his own party, who would easily be numerous enough to cancel out his tiny overall majority. Nor would the diehard pro-EU fifth of Conservative MPs ever accept any referendum in which the only options were that and withdrawal.

An Opposition amendment simply declaring the renegotiated settlement unacceptable ought therefore to be enough to destroy it, and to destroy David Cameron with it.