Nicholas Soames has represented the electoral area of Mid Sussex

Nicholas Soames, the grandson of Britain's World War Two leader Winston Churchill, said he would vote against Prime Minister Boris Johnson on Brexit on Tuesday, a step that enforcers have warned would lead to expulsion from the Conservative Party.

"I will be voting against the government tonight with a very heavy heart," Soames said. Johnson's party officials had warned that rebels would lose the parliamentary party "whip" if they vote against the government.

Soames, 71, who was knighted by Queen Elizabeth in 2014, has represented the electoral area of Mid Sussex, south of London, since 1997 having previously been Member of Parliament for nearby Crawley.

As a young boy, Soames said he was unaware of his grandfather's significance and has recounted how, when aged five, he once visited Churchill in his bedroom and asked him: "Grandpapa, is it true that you are the greatest man in the world?"