Former British Prime Minister Boris Johnson announced on Friday evening his resignation from the House of Commons (Parliament) against the backdrop of a parliamentary inquiry into the "Party Gate" scandal, which focused on Johnson's violation of social distancing laws during the Corona pandemic at parties held at the Government House in 10 Downing Street.

The resignation of the 58-year-old Johnson, which became effective immediately, means a by-election to choose who will succeed him in his slim majority seat, putting further political pressure on incumbent Prime Minister Rishi Sunak.

A year after being ousted from Downing Street by a majority following three years in power that saw a series of scandals, Johnson remains under parliamentary inquiry to determine whether he misled parliament in the "Party Gate" case.

Johnson resigned from the House of Commons after reviewing the report of the Parliamentary Benefits Committee following an investigation into possible misleading Parliament.

He said he was resigning from parliament because it was "clear" that the committee was "determined to use the measures against me to expel me from parliament".

"I am very sad to leave parliament — at least for now — but above all I am dismayed that I was forced to leave in an undemocratic way," the former prime minister said in a statement, accusing the committee of "gross bias."

Parliament's Benefits Committee has the power to recommend that Johnson be suspended from parliament for more than 10 days if it finds that he has recklessly or deliberately misled the House, which could lead to an election for his seat.

"I was forced out (of Parliament) by a small handful of people without evidence to support their assertions and without the approval of even members of the Conservative Party as well as the wider electorate," Johnson said in a statement.

He accused the committee of having released a yet-to-be-published report that was "full of fallacies and biases" without having "any official opportunity to challenge what they say".

Johnson has struggled for his political future in the face of a parliamentary inquiry into whether he misled the House of Commons by saying all Covid-19 rules had been adhered to even though parties were held in government buildings during lockdown.

Johnson was forced to resign as prime minister last summer after a series of scandals, led by concerts in Downing Street during a period of health restrictions imposed to curb the coronavirus.