Former prime minister Sir John Major says grassroots Tories were right to feel “unsettled” by “bewildering” changes such as equal marriage, but warns there’s “no choice but to deal with this new world.”

The Telegraph reports in his speech to the South Norfolk Conservative Association’s annual dinner on Friday evening, Sir John said members were right to feel “unsettled” by “bewildering” changes such as the Coalition Government’s decision to legalise same-sex marriage in England and Wales.

The 70-year-old said: “Social mores have moved on from the way in which we were brought up, with the values that we had. They have moved and changed. And that is why issues such as gay marriage have proved so toxic for the Conservative Party. Because for many Conservatives, people who are conservative because their instinct is to conserve, to change slowly.

“We may be unsettled by them, but David Cameron and his colleagues have no choice but to deal with this new world. They cannot Canute-like order it to go away because it won’t.”

Sir John, PM and Conservative Party leader from 1990 until 1997, announced his support for equal marriage in December 2012, giving full praise to David Cameron.

“The prime minister’s instinct to support equal marriage is a courageous and genuine attempt to offer security and comfort to people who – at present – may be together, yet feel apart,” said Sir John.

“I fully understand that there are many who will find this difficult to accept, as will the churches.

“But the prime minister has made it clear that the churches will be free to make their own decisions upon whether to conduct such marriages – and that is entirely the right approach.”

Sir John added: “We live in the 21st century and must move on: every couple should have the opportunity and the right to formalise their relationship.”

Defence Secretary Philip Hammond, one of the most vocal critics of equal marriage in the cabinet, recently said he had been “shocked” at the speed of the reform. But the senior Tory MP conceded that eventually he will be “quite comfortable” with the reality of same-sex couples marrying in England and Wales.