‘He’s gone full Trump’: Tories turn on Boris Johnson over Partygate

Tory support for Boris Johnson is draining away tonight as party grandees likened his response to a cross-party parliamentary inquiry into whether he misled MPs over “Partygate” to the lies of former US president Donald Trump.

Several Conservative MPs in senior positions reacted with disbelief after Johnson and his dwindling band of allies questioned the work of the independent Commons privileges committee and accused it of an “outrageous level of bias”, after it said on Friday there was a significant volume of evidence suggesting that the former PM may have misled parliament.

Referring to Johnson and his backers, a senior MP who is well informed about Partygate said: “They have gone full Trump. It is wicked. Where will this end? They are desperate.” Another grandee said Johnson was “just like Trump, saying black is white, white is black”.

Tobias Ellwood, Tory chair of the defence select committee, said the prime minister, Rishi Sunak, had shown real leadership with last week’s deal on the Northern Ireland protocol, but warned that the progress risked being undermined by Johnson. In a reference to the ex-PM’s behaviour, Ellwood added: “If we now stay united and disciplined we could win the general election but not if this latest distraction turns into a Trumpian drag anchor.”

Other Tories in high positions in the party said Johnson may have committed contempt of parliament in the past 48 hours alone – by attacking, deriding and undermining the work of a committee which was specifically authorised by the Commons to look into whether he had told the truth to MPs.

Sir Bob Neill, Tory chair of the all-party justice select committee and a lawyer, told the Observer: “It is wrong for anyone to try to undermine the work of a parliamentary committee.”

Johnson’s friends claim that the appointment by Labour leader Keir Starmer of former civil servant Sue Gray – who conducted the inquiry into Downing Street lockdown parties last year – as his chief of staff, showed that Partygate was a politically inspired plot to oust a Brexit-supporting PM and to benefit Labour.

MPs backing Johnson plan to table urgent questions in the Commons on Monday about Gray’s appointment, which one told the Observer they regarded as a “constitutional outrage that completely undermines the civil service”.

It is expected that the government advisory committee on business appointments (Acoba) may delay Gray’s start date by up to two years to minimise concerns over potential conflicts of interest – pushing it back beyond the next general election.

Meanwhile, as Johnson’s allies accused it of staging a “political show trial”, the privileges committee issued a statement specifically countering his and his supporters’ suggestions that it had relied on Gray’s report to reach its own interim findings.

It said none of the evidence from witnesses it had amassed was from Gray and that all of it had been independently verified and compiled. Committee sources said MPs had not and did not intend to take evidence from Gray. They said its evidence included written statements from 23 witnesses as well as WhatsApp messages, photographs from the official Downing Street photographer, and other material provided by government. “It is 100% wrong to say what there is [is] from Gray,” an MP said.

A Tory MP chairing a different Commons committee said: “It is obvious Boris is just trying to find a way out of all this. Any fool can see that.”

On Saturday night, a friend of Johnson, authorised to speak on his behalf, went further in attacking the privileges committee, which is chaired by Labour’s Harriet Harman, but has a Tory majority. The friend said it was “made up of politicians who are already on record saying they think Boris is guilty” and that its investigation “was tainted before it even began”.

The friend added: “This is a political show trial with an outrageous level of bias, orchestrated by Labour to the benefit of Keir Starmer.”

Using Johnson’s knowledge of the classics he went on: “It breaches the longstanding principle of natural justice – nemo judex in sua causa – no one can judge a case in which they have a political interest, and where they have already said the individual is guilty.

“And now we learn the committee intends to rely on the work of none other than Keir Starmer’s chief of staff. How can this process possibly be fair?”

Downing Street refused to be drawn on whether Rishi Sunak continued to back the privileges committee. Sources said it was entirely independent of government and so it would be inappropriate to comment on its work.

On Friday the committee published a 24-page report suggesting that breaches of [lockdown] guidance would have been “obvious” to Johnson at the time he was at the gatherings.

It said there was “evidence that the House of Commons may have been misled” by Johnson who had told it that “all guidance was followed completely” during the gatherings.

Johnson responded to Friday’s interim report by insisting that it had “vindicated” him because it had produced “no evidence” that he had lied to parliament.

The Observer understands that the report was published by the committee after Johnson’s own lawyers asked for information about the issues that would be raised when the former prime minister gives evidence before its seven MP members later this month.

Related: Boris Johnson must face ‘repercussions’ if he misled MPs, Labour says

Sources close to the committee said the interim findings were made public because it was answerable to parliament and the public, not to Johnson alone.

In his initial response to the committee’s findings on Friday, Johnson said: “The committee has produced a report which I believe totally vindicates me because there is no evidence whatsoever that when I stood up in parliament I said anything I did not believe and therefore there is no contempt.’

He went on to say it was “surreal to discover that the committee proposes to rely on evidence culled and orchestrated by Sue Gray, who has just been appointed chief of staff to the leader of the Labour party”.