A majority of Conservative and UKIP supporters are in favour of equal marriage, a new Ipsos MORI poll shows.

In a survey of 1,002 adults conducted at the start of the month, 61% of Tory voters and 54% of would-be UKIP voters said they agreed with the principle of same-sex marriage.

Support rose to three-quarters among Labour and Liberal Democrat supporters.

The proportion of Britons who think gay couples should be able to marry has more than quadrupled in the four decades since 1975.

Sixty nine percent now agree with the statement that “homosexual couples should be allowed to marry each other”, whilst just over a quarter (28%) disagree. When the same question was asked in November 1975, support for same-sex marriage stood at 16% (with 53% disagreeing).

Opinion varies between generations.

Almost nine in ten (88%) of 18-34 year olds think that gay couples should be able to marry each other, but a minority (43%) of those aged over 65 think the same way.

Simon Atkinson, Assistant Chief Executive at Ipsos MORI, said: “It is very unusual, even over a period of 40 years, to see such a sea change in public attitudes.

“People in Britain are clearly behind the recent legislation on gay marriage – a rare example of Parliament and public opinion being very much in tune with each other.”

Last month, UKIP leader Nigel Farage said equal marriage meant “opening up a very big can of worms” – whilst refusing to confirm whether he supported the principle of the reform.

His equivocation came after an apparent breakdown in internal communication regarding the party’s position.

PinkNews received answers to a readers’ Q&A confirmed by an official spokesman to have been approved by Nigel Farage which stated UKIP was reviewing all of its policies including its previously stated opposition to same-sex marriage.

One day later after the Q&A was published, Mr Farage released a statement reiterating the party’s opposition to same-sex marriage, claiming the answers to the Q&A were sent in error.