France is next in line to legalise same-sex marriage, according to a disputed bill pushed by President Francois Hollande on Wednesday, which would defy opposition from the country's Roman Catholic and conservative leadership.

Currently, less than a dozen countries in the world have legalised gay marriage, although most of them are in Europe.

Denmark, Norway, Sweden, Spain, Portugal, Netherlands, Iceland and Belgium have all moved away from the traditional definition of marriage between one man and one woman, and Britain is also considering changing its marriage laws.

The top ministers in France have already approved the measure, marking another successful agenda for Hollande's liberal campaign, The New York Times reported. The president has called the bill "progress for all society".

The new law will redefine marriage as "contracted between two persons of different sex or of the same sex", while the words for "father" and "mother" in French will be replaced by "parents" – allowing them also to start adopting children.

Christiane Taubira, France's justice minister, has also described the bill as "marriage for all" and has said that it comes as response to a "demand for equality".

While supported by the majority of the French population, it stands in stark contrast to the wishes of the conservative opposition in France, who have warned that such a breakaway from traditional values will signal the end of the traditional family unit.

"It's the end of the family, the end of children's development, the end of education. It's an enormous danger to the nation," said UMP Senator Serge Dassault on the radio show "France Culture".

Although France has felt a move toward secularism in recent years, the dominant religious voice there remains the Roman Catholic Church – which is also very much opposed to such changes. Cardinal André Vingt-Trois, the Roman Catholic Archbishop of Paris, has called the bill a "deception", and has questioned how "the marriage of a few imposed on everyone" means that France is working toward equality.

"When we defend the right of children to build their personality with reference to the man and the woman who gave them life, we are not defending a particular position," the cardinal said.

Gilles Bernheim, the chief rabbi of France, added: "There would not be courage and no glory in voting a law by using slogans more than arguments and by complying to the dominant political correctness."