Pope John Paul II denounced the "marginalisation" of religion in the continuing development of the European Union.
The 81-year-old pope said it was "both an injustice and an error of perspective" that religious communities were ignored during the EU's Laeken summit which established a Convention to look into EU reform and expansion.
"No explicit mention was made of communities of religious believers among the partners who are to contribute to the reflection on the Convention instituted at the Laeken summit last month," the pontiff said.
"The marginalization of religions, which have contributed and continue to contribute to the culture and humanism of which Europe is legitimately proud, strikes me as both an injustice and an error of perspective."
The pope made the comments in an address to diplomats at the Holy See.