Francis Maude: Tories must modernise or face 'oblivion' - Telegraph.co.uk

"Today the Conservative Party today is closer to being a genuinely contemporary party," he wrote.

"But we have to stay abreast of evolving social norms. We can't look like we want to turn the clock back to an imagined golden era.

"We should not assume that society will be willing to conform to our own expectations if they're out of kilter with the mainstream," he said.

"And we can't drive policy looking back through a rose-tinted rear-view mirror. There's a simple truth that if our social attitudes are seen as backward looking, we will be unelectable."

Mr Maude, a former Tory chairman, said the programme to modernise the party would "never" completed. He said he remained true to core Tory values and was still "realistically eurosceptic" and "an economic liberal".

But he had had changed his views on social questions over the years. "I've become more socially liberal. That's where the party has changed the most as well – but it's where British society has changed even more," he said.

The next decade in politics "will demand even more" reforms, he said.

"As British society continues to evolve so must the Conservative Party, if we are not to face electoral oblivion.

"If we fail to keep pace – fail to understand and influence the spirit of the age – we will be rightly punished by the electorate."

The Prime Minister's outspoken support for legalising same-sex marriages, including in churches and other religious settings, has dismayed many traditional Tories.

More than 100 Tory MPs and peers are opposed to the plans, while grassroots Conservatives have warned that the policy is driving activists away from the party.

Yesterday, Grant Shapps, the Conservative chairman, insisted that MPs would be given a free vote on the "equal marriage" Bill, which is expected to be introduced next year.

The plan has boosted Mr Cameron's popularity among gay voters.

A recent poll by Pink News, a leading online publication for gay people, found six out of 10 of the lesbian, gay, bisexual and transgender people questioned liked the Conservatives more as a result of the policy.