Britain’s parliament has delivered another blow to the political career of former prime minister Boris Johnson, endorsing a report that concluded he deliberately lied over rule-breaking parties.

Johnson abruptly resigned from parliament earlier this month after seeing an advance copy of the findings of a year-long investigation into his conduct during the COVID-19 pandemic when lockdown-breaking parties were held in Downing Street.

The committee published its findings last week concluding that Johnson had deliberately lied to colleagues when he assured the House of Commons that all COVID-19 rules had been followed at all times in government buildings.

The report recommended Johnson should be denied a pass giving him automatic access to parliament and would have recommended suspending him from the House of Commons for 90 days if he had not already resigned.

MPs in the House of Commons voted on Monday 354 to 7 to endorse the committee’s report after a five-hour debate on its findings.

Parliament’s decision to back the conclusions of the report does not stop Johnson from standing again to be a member of the House of Commons, but it is an embarrassing punishment for a politician who was still prime minister a year ago.

Most politicians who spoke in parliament on Monday criticised Johnson’s behaviour, while a handful of his supporters questioned the impartiality of the committee.

Former Prime Minister Theresa May warned Johnson’s supporters not to vote against the committee’s report, saying doing so would erode the public’s faith in democracy.

Jacob Rees Mogg, a minister in Johnson’s government, said it was “perfectly reasonable” to challenge the views of the committee and suggested MPs investigating the former prime minister had “wanted to come to a particular conclusion”.

Johnson, prime minister from the middle of 2019 until September 2022, was one of Britain’s most controversial leaders in recent decades.

Opinion polls show Johnson is currently unpopular with most of the public, but he retains the backing of some Conservative Party members.

Senior politicians in the governing Conservative Party, including Prime Minister Rishi Sunak, skipped the debate on Monday to avoid increasing tensions with party members who remain loyal to the former prime minister.

Sunak, who promised a government of integrity, did not attend the debate in parliament because he was welcoming the prime minister of Sweden and had other meetings, his spokesman said earlier.

Johnson has characterised the committee as a “kangaroo court” and said the report was “intended to be the final knife-thrust in a protracted political assassination”. 

By Andrew MacAskill and Muvija M in London