Gay marriage: Coalition For Marriage's Dr Sharon James
11 December 2012 Last updated at 14:36 GMT
David Cameron was holding "great swathes of the electorate in contempt" over a "sham consultation" about gay marriage, said Dr Sharon James from the Coalition For Marriage campaign group.
She claimed "broken promises" left the consultation invalid as a 500,000-name petition was "relegated to an appendix" while support from abroad for gay marriage was being counted on the plans which were not in the manifesto of any major political party.
She spoke as Culture Secretary Maria Miller, who is also the Minister for Equalities, announced that the Church of England and the Church in Wales will be excluded from the government's planned new law to allow gay couples to marry.