The Brussels-based commission representing Catholic bishops in the European Union will urge EU leaders to recognise the continent's Christian heritage when they publish a major declaration next March.

After a plenary session the Commission of Episcopates of the European Community (Comece) said: "For all its founders, the Christian imprint on the European project was an indisputable fact. Their ambitions were deeply rooted in a set of common values with respect for human dignity at its core. In the  context of new challenges, these values need to be redefined." The statement said the planned Berlin Declaration would provide a "unique opportunity" for EU leaders to "set out the values they share and the ambition to make these values real".

"The European Christian and humanistic heritage is the origin, and the Christian faith of a majority of EU citizens the living source, for our common values," said Comece, which includes bishops' conferences from the EU's 25 member states, with observers from Bulgaria, Romania, Croatia and Switzerland. "The Berlin Declaration should therefore reflect the religious and humanistic motivations of EU citizenship, in laying the foundations for a new political and legal framework."

EU politicians have often been accused of ignoring the role of Churches and religious faiths in Europe, which were not mentioned in any EU documents until the late 1990s. Although the stalled 2005 Constitutional Treaty acknowledged the continent's "cultural, religious and humanist inheritance", its lack of support from Churches was widely seen as a key reason for its failure.

The March declaration, to be signed jointly by the European Commission and European Parliament during Germany's rotating presidency, will mark the fiftieth anniversary of the Treaty of Union, which created the European Economic Community. By committing member states to "shared values and ambitions", the document is expected to facilitate fresh attempts in 2008 to establish the Constitution, which has already been ratified or approved by 16 EU countries.

In its statement, Comece said church leaders would set out their concerns at a meeting early next year with the Commission and Parliament presidents, José Manuel Barroso and Josep Borrell.