Boris Johnson is resigning as an MP after accusing a Commons investigation into whether he misled Parliament over partygate of attempting to "drive me out".

The former prime minister, in a statement to the media, compared the Privileges Committee probe to a "kangaroo court" as he announced his intention to step down as MP for Uxbridge and South Ruislip.

He said, after receiving a letter from the committee, he believed it was "determined to use the proceedings against me to drive me out of Parliament".

"It is very sad to be leaving Parliament - at least for now - but above all I am bewildered and appalled that I can be forced out, anti-democratically, by a committee chaired and managed, by Harriet Harman, with such egregious bias," he said.

The announcement, coming only hours after his resignation honours list had been published, means the Conservatives are likely to face a tough battle to hold onto the London seat at a by-election.

It was the second by-election triggered on Friday following former culture secretary Nadine Dorries' decision to quit the Commons immediately, rather than wait until the next election.

The Privileges Committee has been investigating whether Mr Johnson misled MPs when he assured them that Covid rules were followed in No 10 following allegations of lockdown-busting parties.

In a lengthy statement, he accused the committee of producing a yet-to-be-published report "riddled with inaccuracies and reeks of prejudice" while providing him with "no formal ability to challenge anything they say".

He said the panel of MPs had "still not produced a shred of evidence that I knowingly or recklessly misled the Commons".

But he said he thought their "purpose from the beginning has been to find me guilty, regardless of the facts".

He said: "So I have today written to my association in Uxbridge and South Ruislip to say that I am stepping down forthwith and triggering an immediate by-election.

"I am very sorry to leave my wonderful constituency. It has been a huge honour to serve them, both as mayor and MP."