Christian religious tradition has "no place" in a new constitution for Europe, according to MPs involved in negotiations on the EU's future.

Gisela Stuart and David Heathcoat-Amory, parliament's two delegates to the Convention on the Future of Europe, are opposed to a "religious reference" in any future statement of the political principles underpinning the European Union.

Behind the scenes moves by some of Europe's powerful centre-right politicians and the Catholic church to get a commitment to religious belief in a declaration of EU "values" has opened up deep divisions.

The Pope has urged the convention to reinforce the "cement of that extraordinary religious, cultural and civic heritage that has made Europe great down the centuries".

Religious questions are also high on the enlargement agenda.

Catholic Poland is concerned that its entry into the EU will see an erosion of the country's tough anti-abortion and contraception stance.

The issue is set to come to the fore as Poles prepare for a referendum on EU membership amid fears that a church-led "no" campaign could scupper accession.

The question of Christianity has also loomed large as Turkey pushes at the EU door.

The secular Muslim country's efforts to join Europe's club has prompted some to claim that Christian values underpin the EU ethos leaving no room for Islam.

Convention chairman Valery Giscard d'Estaing said at the end of last year that Turkey was "not a European country" and warned that allowing it to join the EU would "be the end of Europe".

Stuart argues that such a stance is out of step with today's secular and ethnically diverse European Union.

"Assertion of Christian religious belief clearly has no place in the constitution," she told ePolitix.com.

"EU values have grown out of Christian traditions but today we have huge Muslim communities and I think that would be the wrong direction."

Heathcoat-Amory has a fundamental objection to the whole idea of an EU constitution which "gives rise to these kinds of controversies".

Calls for a "God" reference in any statement of European principles, he says, are meaningless outside a Christian context, which he claims would alienate Turkey.

"I am not in favour," he told ePolitix.com. "If it means anything it is the Christian God and what are the Turks to make of that?"

"It is one thing to have a constitution for a people like the Americans but raises issues in a diverse Europe."

The question is a live one for centre-right Christian democrat parties with close links to the Catholic church.

A submission drafted by a conservative German MEP, Joachim Wurmeling, has already attracted 19 backers on the convention.

"[EU] values shall include the values of those who believe in God as the source of truth, justice, good and beauty as well as of those who do not share such a belief but respect these universal values arising from other sources," he suggests.

British gay and lesbian humanists have written to the convention's leadership urging delegates to reject the Wurmeling approach.

The UK Gay and Lesbian Humanist Association claims that "as far as homosexuals are concerned, the 'heritage' of religion in Europe throughout the centuries has been one of persecution".

Campaigners are concerned that as strongly Catholic countries such as Poland join the EU "the hand of the Vatican with its grotesquely anti-gay agenda" will be strengthened.

"The Pope is pushing for more influence in the EU's decision making processes. It is important that he does not succeed," said the group.

"Homosexuals throughout Europe have looked to the EU to put right the many discriminations that existed. The last thing we need is for religion to reassert its influence."