Boris Johnson ally Nigel Adams has said he is standing down as an MP with “immediate effect”, triggering another by-election.

The move, which follows the former prime minister’s resignation on Friday, will leave Prime Minister Rishi Sunak facing a third by-election – this time in Mr Adams’s Selby and Ainsty constituency.

He previously said he would quit at the next general election but has joined Mr Johnson and Nadine Dorries in resigning now.