Taxpayers are expected to foot a massive £222,000 bill for Boris Johnson's legal defence against allegations he misled Parliament over Partygate.
Today a senior civil servant confirmed that the estimated cost in defending the shamed former Prime Minister had soared by more than £90,000 since 2022.
And it could go up still further, Cabinet Office permanent secretary Alex Chisholm admitted.
The sum has sparked immediate criticism, with the Lib Dems branding it a "sleazy new low".
Mr Johnson, now a backbench MP, faces a probe over his denials of lockdown-busting gatherings in No10, with hearings likely to begin in March.
He is being investigated by the House of Commons Privileges Committee, which will determine whether he committed contempt of Parliament - an allegation he denies.
Solicitors firm Peters and Peters were awarded a contract worth £129,700 to provide Mr Johnson with advice during the investigation.
Mr Chisholm confirmed that the sum had risen dramatically, and could not guarantee it wouldn't go up even further.
Pressed on whether the amount could rise still further, Mr Chisholm said: "It could potentially exceed that."
Liberal Democrat Chief Whip Wendy Chamberlain said: "While the British people battle with a cost-of-living crisis, this Conservative Government seems more interested in helping Boris Johnson with his cost-of-lying crisis. This is a sleazy new low for this Government, dragging politics into the gutter.
"People will be outraged that hundreds of thousands of pounds of their money will be used to defend a lying lawbreaker who disgraced the office of Prime Minister.
"Rishi Sunak needs to step in immediately, stop this fund and apologise for his Government's chaotic track record of defending the indefensible."
At a meeting of the Commons Public Administration and Constitutional Affairs Committee on Thursday, Tory MP David Jones questioned the spending.
He asked Mr Chisholm: "Is it normal for the government to pay for legal advice in such circumstances?"
The civil servant responded: "It is normal, there's an established precedent across multiple administrations that former ministers can be supported with legal representation after they've left office when the matters relate to their time and conduct as a minister."
Mr Chisholm said the amount had been increased due to the length of the committee inquiry.
He said: "At the moment we have estimated that it would be up to a figure of £200,000, which has been published, £222,000 to be precise.
"We hope and expect that will be a maximum figure but obviously we don't want to anticipate and certainly could not regulate the conduct of the committee, which is entirely up to them."
Mr Chisholm told the committee the contract with Peters and Peters had received "very full scrutiny from all the relevant people".
The contract with Peters and Peters has already paid for legal advice from leading KC Lord Pannick, who has produced two opinions on the inquiry.
The first was published on the Government's website in September 2021 - claiming the Privileges Committee was adopting an "unfair procedure" and a "fundamentally flawed" approach.
But this was rejected by the committee, which said it was based on "a systemic misunderstanding of the parliamentary process and misplaced analogies with the criminal law".
Lord Pannick went on to publish a second opinion, but this has not been published.
Cabinet Office minister Oliver Dowden said he could not confirm why, because it happened before he took on the role.
Downing Street repeatedly dismissed the Mirror's revelations about lockdown breaking parties, which later led to police fines for Mr Johnson and the new PM Rishi Sunak.
The Metropolitan Police dished out 126 fixed penalty notices to 83 people over 12 pandemic gatherings in Downing Street and Whitehall, including six events Mr Johnson is believed to have attended.
Whitehall enforcer Sue Gray published a damning report on the extent of the boozing, including wine on the walls, vomiting and a brawl, as well as a lack of respect for cleaners and security staff.
The Privileges Committee probe “includes but is not limited to” four statements Mr Johnson made in December 2021 in the Commons, where he denied parties had taken place in No10.
He said “all guidance was followed” - a claim he later corrected, but said he thought was right at the time - and also explicitly denied there had been a bash on November 13 2020.
But the PM was later pictured holding a glass of fizz at a leaving do on that day - which he has since claimed it was his “duty” to attend.
