Rishi Sunak faces mounting woes as third Tory politician resigns in 24 hours

Nigel Adams stepped down from his role as Member of Parliament on Saturday

Nigel Adams is the latest Conservative MP to quit parliament. EPA

British Prime Minister Rishi Sunak faces a third by-election test after a close ally of Boris Johnson resigned on Saturday with “immediate effect”.

In a tumultuous 24 hours for the Conservative Party, Nigel Adams announced that he was following the former prime minister and former culture secretary Nadine Dorries’ lead in quitting Westminster.

“Yesterday, Selby Conservatives selected an excellent new parliamentary candidate," Mr Adams said in a tweet.

“I’ve today informed the chief whip that I will be standing down as a Member of Parliament with immediate effect.

“It has been an honour to represent the area where I was raised [and] educated.”

The departures from Parliament of Mr Johnson and his ally Nadine Dorries have triggered by-elections for two Conservative-held constituencies that Mr Sunak must now defend.

The opposition Labour Party, which has a roughly 16-point lead over Mr Sunak's Conservatives in opinion polls, said it relished the prospect.

"We will be fighting to win in those constituencies," Labour's deputy leader Angela Rayner told the BBC on Saturday.

"They've created a by-election because both of them (Johnson and Dorries) have thrown their toys out of the pram."