A survey of attitudes of MPs has found that many Conservative members have a markedly different social outlook from leader David Cameron.
The poll, carried out by Populus, spoke to 128 MPs overall, 39 of whom were Tories.
54% of the Conservatives did not think that gay people should have equal rights with heterosexual people.
83% of the 70 Labour MPs and 92% of the 13 Lib Dems polled supported gay rights.
Tory leader David Cameron has spoken of his support for civil partnerships and the party frontbench supported recent gay rights legislation.
However, in March Tory MPs in the House of Commons forced a vote on the Sexual Orientation Regulations. The regulations passed by 310 votes to 100.
29 Tory MPs voted in favour of the regulations, 85 against.
Ten Labour and four Lib Dem MPs voted against the regulations, which outlawed discrimination on the grounds of sexual orientation when accessing goods and services.
The Chancellor of the Exchequer voted in favour of the regulations, as did Ruth Kelly, Secretary of State for Communities and Local Government, who is the cabinet minister responsible for equality.
It was the first time either of them had voted in favour of a gay rights bill.
Tory MPs Ann Widdecombe, former Chancellor Kenneth Clarke and former leader Iain Duncan Smith voted against.
The party had previously said that their MPs would be given a free vote.
Previously a group of Tory MPs attempted to block the Sexual Orientation Regulations at committee stage, arguing that they had not been given proper time to debate them.