David Cameron would be acting like a "dictator" if he allowed same-sex unions to be called marriages, the Archbishop of York has said.
Marriage must be between a man and a woman, he told the Daily Telegraph.
Dr Sentamu also said the Church should do more to avoid its leadership being mainly white and middle class.
The government will open a consultation on the issue of same-sex marriages in March. A consultation on the subject by the Scottish government ended last month. Read more