Turkey's chances of EU membership are in doubt, warns Barroso

Jose Manuel Barroso, the European Commission president, has cast doubt on Turkey's prospects of European Union membership, as heads of government wrangled over moves to revive the moribund European constitution in 2008.

Mr Barroso said that getting Turkey into the EU would be "very difficult " and added many in Europe see the 70 million-strong, mainly Muslim nation as "culturally different".

A crisis in negotiations on Turkish membership of the EU was narrowly averted on Monday. However, diplomats believe the problems have simply been postponed until autumn, when Turkey will be asked to open up its ports to Cypriot-registered vessels. Yesterday Jean-Claude Juncker, the Prime Minister of Luxembourg, told the French daily La Croix: "If Turkey were not to implement this condition this year, my view is that the negotiations will have to be postponed."

Asked whether Turkish membership of the EU will ever happen, Mr Barroso told the BBC: "I think it is possible but it will be a very difficult task ... demanding for them but also demanding for us here to be ready to accommodate such an important, big country that is seen by many of us as culturally different from mainstream Europe."

EU leaders will decide today on a form of words to describe their approach to future enlargement and to what extent they need to take into account the bloc's capacity to absorb new countries. That could send a signal to Turkey that it will be difficult to accommodate. The other issue expected to dominate the Brussels summit, which ends today, was the EU constitution and how to find a means of moving on from the debacle of 2005, when the treaty was rejected by voters in the Netherlands and France.

Britain's Labour Party leaders are preparing to drop their pledge to hold a referendum on a new EU treaty. They will argue that the changes could be approved by the UK Parliament if they were less significant than the constitution rejected by Dutch and French voters a year ago.

The plan to revive the ill-fated EU blueprint could cause a headache for Gordon Brown, who is widely expected to succeed Tony Blair as prime minister, in the run-up to the next general election, which is expected in 2008 or 2009.

EU leaders are likely to agree to kick decisions on the future of the constitutional treaty into touch for another year at least. Wolfgang Schüssel, the Chancellor of Austria, which holds the EU presidency, set out a timetable which would mean Germany and France taking the lead on how to revive the charter.

Germany, which will hold the EU's rotating presidency in the first half of 2007, would restart efforts to get all EU nations to ratify the constitution. That would mean decisions being taken in 2008 at the end of France's presidency. Britain pressed for a loose form of words, insisting that the result of the pause for reflection must not be pre-judged. It favours a minimalist change, though it acknowledges that the least that will be required will be a small change to the Nice Treaty.

British ministers admitted privately that a referendum could easily be lost and that they would seek to drop the promise made by Mr Blair in 2004 if the changes were small-scale. Mr Blair's ally, Peter Mandelson, the European Trade commissioner, made clear that Downing Street regards the EU constitution in its current form as dead. "We have no alternative but to find a new way, a new route to follow in order to find some answers to the original questions that were put," he told Radio 4's PM programme.

But dropping the referendum pledge would be highly controversial. Yesterday Labour and Liberal Democrat figures said a referendum should be held.

"It is the only way that a government can secure the consent of the people in this matter," Gisela Stuart, a Labour MP who helped to draw up the constitution, told an Open Europe seminar. Vince Cable, the Liberal Democrats' deputy leader, said anything more than "limited technical changes" would require a referendum. A revised treaty will be required if Croatia is to join the EU because the current arrangements cover only the admission of two more countries, and Romania and Bulgaria are expected to join the bloc next year.