European church leaders have revived efforts to include a "God clause" in the EU constitution after Germany sought to reignite the current drafting process.

Leaders from Catholic and Protestant churches, particularly in Germany, are appealing to German Chancellor Angela Merkel to use Berlin's six-month EU presidency to speak in favour of a reference to God in the EU constitution, reports Reuters.

Last year, Merkel expressed her support for the "God clause" following her visit in August to Pope Benedict XVI.

She said, "we need a European identity in the form of a constitutional treaty and I think it should be connected to Christianity and God, as Christianity has forged Europe in a decisive way."

Now it seems Merkel is prepared to resurrect the debate over the inclusion of a reference to God. She told Focus magazine at the weekend, "Europe must continue to consider this issue."

The "God clause" supporters face fierce opposition, however. The current draft makes reference to Europe's "cultural, religious and humanist heritage" agreed on in 2004 after a high-profile campaign by the Vatican and traditionally Catholic countries.

"When European leaders are grasping around to eke out some form of unifying statement on the 50th anniversary of the Treaty of Rome, they will not wish to put any new dividers in," said Hugo Brady of the Centre for European Reform in London, in the Reuters report.

One EU ambassador in Brussels agreed: "There is no chance whatsoever of reopening that debate." The 2004 draft was rejected by referendums in the Netherlands and in France, the leading opponent of the "God clause".

The most the churches could hope for, according to Brady, is a clearer reference to religion in a declaration that EU leaders will issue in Berlin on March 25, the 50th anniversary of the EU's founding Treaty of Rome.

Church leaders in Europe have become very vocal in their support recently of a reference to Europe's Christian heritage in the EU constitution.

Cardinal Karl Lehmann, head of the German Catholic Bishops' Conference, and Munich's Cardinal Friedrich Wetter have spoken out this month for a mention of faith in Europe's heritage. "We don't want a God-less state and a God-less Europe," Wetter said.

In Portugal, Lisbon Cardinal Jose Policarpo said, "it would be a cultural disgrace and ignorant not to mention Europe's Judeo-Christian past in the prologue to a future treaty."

The Evangelical Church in Germany, one of Europe's leading Protestant churches, said it "continues to stand for the inclusion of a clear reference to our responsibility before God and the importance of the Judeo-Christian tradition".

The push comes days after the new president of the European Parliament, Hans-Gert Poettering, said that, despite his personal convictions, he would no longer push for a reference to God in any revised EU constitution.