In a letter to a gay constituent, Andrew Smith, Paterson talked enthusiastically about recent advances in Britain for homosexuals, The Guardian reported. But he then drew a line on the issue of marriage.
"Having considered this matter carefully, I am afraid I have come to the decision not to support gay marriage," Paterson said.
Cameron argues Conservatives should encourage gays and lesbians to form stable relationships with the benefits of civil marriage. He is meeting considerable opposition from the Church of England and other religious groups and his party's right wing.
Defense Secretary Philip Hammond said recently that the issue is "not the No. 1 priority" and said he would not support introducing legislation. He stopped short of outright opposition.
Smith told the Web site PoliticsHome, which published the letter, that young gays in rural areas like northern Shropshire, which Paterson represents in Parliament, need representatives who will stand up for them.
"It is bizarre that a Cabinet minister can both praise his government's progress on LGBT equality in the same letter that he tells me he won't support my right to marriage equality," Smith said. "Logic eludes this man."