Gay marriage threatens the establishment of the Church of England and could lead to it being forced out of its role of conducting weddings on behalf of the state, it has claimed.

The Church of England said introducing same-sex marriage would lead to an unprecedented clash between its own canon law, that marriage is between a man and a woman, and that of Parliament.

It also warned that in spite of ministerial assurances that churches would not have to conduct gay marriages, it would be "very doubtful" whether limiting same-sex couples to non-religious ceremonies would withstand a challenge at the European Court of Human Rights.

The submission from the Church of England will add to pressure on David Cameron, who has spoken out in support of gay marriage.