Boris Johnson will submit a written dossier of evidence to MPs as he attempts to clear his name over allegations he misled Parliament over the partygate scandal.
The former prime minister will provide the statement to the Privileges Committee as he battles to save his political career.
Mr Johnson will appear before the panel on Wednesday for a televised grilling, and it is expected he will submit his written evidence before then.
They are examining evidence around at least four occasions when he may have deliberately misled MPs with his assurances to the Commons that rules were followed.
Allies of Mr Johnson said he would provide a “detailed and compelling” account to the committee before his appearance , showing that he “did not knowingly mislead the House”.
He will also publish messages which show that other senior figures in Downing Street believed the gatherings were covered by the “workplace exemption” in the lockdown rules.
The committee’s investigation is being chaired by Labour’s Harriet Harman, although the seven-strong panel has a Tory majority.
The committee will publish its findings on whether Mr Johnson committed a contempt of Parliament and would make a recommendation on any punishment, but the ultimate decision would fall to the full House of Commons.
Prime Minister Rishi Sunak has said he would not seek to influence MPs on the committee and indicated he would grant a free vote to Conservative MPs on any sanction that may be recommended.
Asked if he was not concerned that a suspension of more than 10 days could trigger a by-election in Mr Johnson’s Uxbridge and South Ruislip seat, Mr Sunak added: “This is a matter for Parliament, for the House. It’s not right for the Government to get involved.”