Former British prime minister Boris Johnson's written defence in response to an influential parliamentary committee was published on Tuesday and in it he accepts that he misled Parliament over the partygate scandal of Covid lockdown law-breaching parties at Downing Street, but did so in "good faith".

Mr Johnson is due to give oral evidence to the House of Commons Privileges Committee this week and made written submissions ahead of that, in which he criticises the panel for going "significantly beyond its terms of reference".

The 58-year-old backbench Tory MP also tries to discredit the cross-party committee's interim report, describing it as "highly partisan".

"I accept that the House of Commons was misled by my statements that the Rules and Guidance had been followed completely at No. 10," reads his evidence.

"But when the statements were made, they were made in good faith and on the basis of what I honestly knew and believed at the time. I did not intentionally or recklessly mislead the House on 1 December 2021, 8 December 2021, or on any other date. I would never have dreamed of doing so," he said.

The former prime minister, whose exit from 10 Downing Street last year had been hastened by the partygate scandal, had repeatedly denied COVID lockdown rules were broken within government quarters when asked in the Commons.

With specific reference to a surprise birthday party for him in June 2020, the former prime minister expresses shock at having been handed a fine for it following a Metropolitan Police investigation because no cake was eaten.

"I was in the Cabinet Room for a work meeting and was joined by a small gathering of people, all of whom lived or were working in the building. We had a sandwich lunch together and they wished me Happy Birthday. I was not told in advance that this would happen. No cake was eaten, and no-one even sang 'happy birthday'. The primary topic of conversation was the response to Covid-19," he writes.

The Covid-19 Bereaved Families for Justice UK group took to Twitter to say that it is "sickening" that Mr Johnson claimed he acted in "good faith" while accepting he misled the House of Commons over partygate.

The parliamentary committee also hit back to say his submission contains "no new evidence" in his defence.

"The evidence strongly suggests that breaches of guidance would have been obvious to Mr Johnson at the time he was at the gatherings," the Privileges Committee had said in its interim report released earlier this month.

Mr Johnson is due to give oral evidence to the committee on Wednesday, following which it will submit its report to British Prime Minister Rishi Sunak. It will be up to him to sign off on any sanction against his ex-boss, which could involve a suspension from Parliament if found to have knowingly misled Parliament.