The legalisation of same-sex marriage removes children from the centre of marriage and “heralds a profound social change” the Catholic bishops of England and Wales have warned.

In a statement, they said that the new law broke “the existing legal links between the institution of marriage and sexual complementarity”.

The statement, signed by Archbishop Vincent Nichols of Westminster (pictured) and Archbishop Peter Smith of Southwark, respectively the president and vice-president of the Bishops’ Conference, said: “In receiving Royal Assent, the Marriage (Same Sex Couples) Act marks a watershed in English law and heralds a profound social change.

Marriage, the statement added, had been “recognised as unique and worthy of legal protection” because it established “a legal framework for the committed relationship between a man and a woman and for the upbringing and care of their children”.

It continued: “The new Act breaks the existing legal links between the institution of marriage and sexual complementarity.

“With this new legislation, marriage has now become an institution in which openness to children, and with it the responsibility on fathers and mothers to remain together to care for children born into their family unit, are no longer central. That is why we were opposed to this legislation on principle”.

The statement welcomed amendments made by the House of Lords which it said “significantly strengthened the legal protections in the Act for the Churches”.

It also welcomed an amendment made by the Government to the Public Order Act which says that “discussion or criticism of marriage which concerns the sex of the parties to the marriage shall not be taken of itself to be threatening or intended to stir up hatred”.

The statement said that the new legislation meant that individuals “are therefore protected from criminal sanction under the Public Order Act when discussing or expressing disagreement with same sex marriage”.

However they expressed concern that amendments aimed at providing legislative clarity for schools with a religious character had not being accepted.

It said: “Given the potential risk that future guidance given by a Secretary of State for education regarding sex and relationships education could now conflict with Church teaching on marriage, we were disappointed that an amendment to provide this clarity was not accepted.

However the Bishops acknowledged that the Government that schools, when teaching on marriage with a religious character could “take into account other matters, including in particular relevant religious tenets”, and that “having regard to a provision does not mean that it must be followed assiduously should there be good reason for not doing so”.

These assurances, the Bishops added “go some way to meeting the concerns we and others expressed”.