Bendor Grosvenor, who presents Britain's Lost Masterpieces for the BBC, said that the “broad church” of the Conservative Party had been driven into the crypt

A prominent art historian and former Conservative adviser has cut ties with the Tories, saying that it is time to “destroy” the party.

Bendor Grosvenor, who is a co-presenter of BBC4’s Britain’s Lost Masterpieces, has voted Conservative for more than 20 years but blames “Johnsonian Toryism” and Brexit for driving “the broad church into the crypt”.

Grosvenor, 41, said that scandals, political purges and hardline support for leaving the European Union was driving many old-fashioned, liberal conservatives away.

The broadcaster, who was educated at Harrow and Cambridge and lives near Edinburgh, says he will now vote for the SNP.

He became a Tory member in 1997 and took an active role in the party after meeting Hugo Swire, the former Conservative