Conservative peer Lord Ashcroft believes the leadership of the Tory party needs to offer a “sincere apology” for equal marriage if it’s to reconnect with its grassroots members.

The former deputy chairman of the party said it was one of several polices to have damaged support among many Tory voters who had now flocked to UKIP.

The Conservatives have a year to “reconnect with these supporters”, Lord Ashcroft said on Saturday.

“This will probably mean a swallowing of pride with a sincere apology for the way gay marriage was introduced and, perhaps, an admission that HS2 is not the right policy, and immigration is not under control,” he added.

On Monday, Conservative blogger Tim Montgomerie also said equal marriage had contributed to the rise of the UKIP.

The journalist and political commentator suggested it was wrong to call UKIP supporters bigots or “racist”.

A poll published last month showed support for equal marriage among Conservative and UKIP supporters had increased.

Another poll, commissioned by the anti-gay Coalition for Marriage days before last week’s local and European elections, found that 23% of Tory supporters felt same-sex marriage was a reason not to vote for the party.

Yesterday, UKIP’s newly elected MEP for Scotland claimed same-sex marriage “breeds homophobia” and that civil partnerships “should be enough”.

David Coburn, who is gay and has been in a same-sex relationship for more than 30 years, was elected on Sunday night as his party’s first MEP in Scotland.

UKIP remains opposed to equal marriage.