Former British Prime Minister Boris Johnson says he is stepping down as a member of Parliament with immediate effect.

In a statement carried by British media on Friday, he says he is quitting to protest a parliamentary inquiry over lockdown-breaking parties held at 10 Downing Street while he was leader.

Johnson accused a House of Commons committee of using the proceedings to drive him out.

He wrote, "They have still not produced a shred of evidence that I knowingly or recklessly misled the Commons" over the parties. He called the inquiry a "kangaroo court".

Johnson was forced to resign as prime minister last year for holding parties at the height of the pandemic in 2020 and 2021.