But several pro-life and religious activists argue the Charter of Fundamental Rights, which is a part of the European Constitution, includes ambiguous definitions of some human rights, which could lead to their interpretation by the EU top court in a way that runs counter to traditional Christian principles.

At the same time, feminist and pro-abortion lobby groups are making it clear they want to use the provisions of the Charter to extend human rights protection in controversial areas, especially in countries with stricter legislation.

Whose rights to protect first?

John Smeaton from the Society for the protection of the unborn children, a London-based NGO, argues that the Charter of Fundamental Rights does not satisfy the expectations of many.

"It is not enough to express a protection of human dignity, while at the same time making possible to violate it through further jurisdiction", he told the EUobserver.

According to Mr Smeaton, once the Charter becomes a legally binding part of the new EU Constitution, Europe could see a similar development to the United States where the rights of women and unborn children have come into conflict.

He says the rights of women have become prioritised leading to pro-abortion rulings.

Similar concerns have been voiced about assisted suicide with respect to the provision on the right for "human dignity" and "mental integrity", according to Mr Smeaton.

Noel Treanor, COMECE secretary general, admits that these fears remain in the Catholic and other churches in Europe.

But he pointed out that the Constitution sets out the areas of competence between the EU and member states and that issues like abortion or euthanasia are matters for individual countries to decide upon.

"However, the future is never totally foreseeable, one does not know in which direction the jurisprudence can develop".

"The church will continue to make a vital contribution to the public debate on these issues", Mr Treanor told the EUobserver.

Pro-life activists disagree, according to John Smeaton. "What we’re seeing on the part of religious leaders is not a courageous enough stance, and a sort of terror to say anything which could sound like anti-Europe".

Pro-abortion groups on alert

Meanwhile, some women and pro-abortion lobby groups are preparing to use the new Constitution to advocate their issues.

Wanda Nowicka, from Polish NGO Astra Network, dealing with sexual and reproductive rights of women in central and eastern Europe, pointed out that even though the Charter is still not strong enough as a legal instrument, "We are going to refer to it, to ensure it would address issues of gender discrimination in some member states".

"The right to safe abortion is an internationally recognised right, but in some countries, like in Poland, Malta or Ireland it is only recognised in theory – if at all - while in practice it is almost or completely impossible for women to exercise it", Mrs Nowicka told the EUobserver.

She doubted that the charter itself could change this, but "at least it would be up to the EU to recommend what should be done so that citizens in, say, Poland, enjoy the same rights as those in Germany or other – more liberal - countries".

Women priests due to EU Constitution?

Opponents of the EU charter also point to a possibility of rulings against the Catholic Church provision on male-only priests.

They argue this could be attacked on the basis of "non-discrimination" rights especially in those countries where priests are financed from public funds.

The current Pope, Benedict XVI, pointed to these concerns in April, saying "the fact that the Church is convinced of not having the right to confer priestly ordination of women, is now considered by some as irreconcilable with the European Constitution".

Patricia Conlan, an EU law expert from the University of Limerick in Ireland, also expects there to be more references to the human rights charter if and when the EU Constitution is ratified.

However, she argues that the Charter does not extend the scope of EU law nor brings in new powers to the Union’s institutions.

At the same time, the EU's top court has so far been reluctant to step into "sensitive areas", which "would point to a modest underpinning of the status quo rather than an extensive development in the mentioned areas", she argued.