The Catholic Bishops Conference of England and Wales said that the passing of same-sex marriage into law "marks a watershed in English law and heralds a profound social change."
Archbishop of Westminster the Most Rev Vincent Nichols and the Archbishop of Southwark Peter Smith said in a statement: "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."
More top news
The train was reportedly carrying 1,300 passengers instead of the usual 600 after a nearby road collapsed.
The United Nations has expressed 'grave concerns' over reports that the so-called Islamic State is using civilians as human shields.
An amateur sculptor offered to step in after the statue was vandalised - but the local priest admits the result is 'shocking to the eyes'.