(Bloomberg) -- Boris Johnson and his senior officials must bear responsibility for the illegal parties held in Downing Street during the pandemic, according to a long-awaited internal probe into the so-called partygate scandal.

“Many of these events should not have been allowed to happen,” civil servant Sue Gray, who was commissioned by Johnson to investigate the allegations, said in her report published Wednesday, which includes details of how officials boasted of getting away with drinks parties. “The senior leadership at the center, both political and official, must bear responsibility for this culture.”

Gray’s full findings were due weeks ago, at a time when many in Westminster predicted they had the potential to end Johnson’s political career. But the report was delayed by a separate police inquiry and attention has since shifted to Russia’s war in Ukraine. Conservative Members of Parliament are now showing far less inclination to try to oust the prime minister.

Still, the revelations have the potential to undermine Johnson, both within his ruling Tory party and especially among the wider electorate. Support for the Conservatives has plummeted over partygate, with voters complaining that officials ignored the tough rules they imposed on the rest of the country.

Johnson is due to make a statement after Prime Minister’s Questions, which begins at 12 p.m., and will tell the House of Commons he is “humbled by the whole experience” and that “we have learned our lesson,” according to a person familiar with the matter.

Naming Names

The report names Johnson, as well as Simon Case, the cabinet secretary and head of the civil service. Martin Reynolds, Johnson’s former principal private secretary who infamously sent staff an email inviting staff to bring their own bottle to a drinks event in May 2020, is also identified.

The question is to what extent these findings affect Johnson’s prospects. In the short-term, that will depend on how Tory MPs react to the findings, given the general sense of what happened in Downing Street is already in the public domain -- if not at the level of detail laid out in Gray’s report.

It’s several weeks since “Waiting for Sue Gray” was the typical response among Conservative MPs when asked if they would seek a change of leader. For would-be rebels, the numbers present a significant hurdle: it would take 54 of them -- or 15% of Tory MPs -- to force a no-confidence vote. To then win it would require a majority of the parliamentary party.

Johnson’s critics argue that events conspired against them, allowing the prime minister -- whose various nicknames among politicians include “Teflon” and “the greased piglet” -- to evade a reckoning.

‘Serious Failure’

Instead of being published at the height of Tory moves against Johnson, Gray’s report was delayed after the police decided belatedly to get involved. That restricted the civil servant to a 12-page interim version, which criticized a “serious failure” of leadership but didn’t trigger a wider rebellion.

The police’s parallel inquiry resulted in Johnson and Chancellor of the Exchequer Rishi Sunak -- who is shown in one of the photos included in the Gray report -- receiving a fine for attending the premier’s birthday party, making him the first prime minister found to have broken the law. In total, police issued 126 fines to 83 people for attending events on eight different dates between May 2020 and April 2021.

At each stage, though, many Tory MPs have pointed to future events as the point when a decision on Johnson’s leadership would need to be made. First it was Gray’s report, then the outcome of local elections in early May, then the police probe. Now it’s Gray’s report again.

Johnson’s parliamentary minders managed to smoke out Conservative rebels who were plotting a putsch in late January. Since then, the conflict in Ukraine and growing worries about the worst squeeze on living standards since the 1950s have concentrated the minds of MPs.

Lacking Options

For the Tories, the lack of obvious challengers to Johnson is a major consideration. Sunak’s popularity has waned as Britain’s cost of living crisis deepened. He’s been further undermined by questions about his tax affairs and was also fined for breaking lockdown rules. Foreign Secretary Liz Truss, another potential candidate, is seen by some as divisive. 

After ITV News published photos showing Johnson proposing a toast at one lockdown gathering, there was still a sense among Tory MPs that Johnson would survive. The pictures, which raised questions about why police didn’t fine the prime minister, didn’t change the narrative on partygate, they said.

For the most part, it’s the usual critics who are calling for his resignation and they have been doing so for months.

Still, the setbacks continue to mount for Johnson, with each photograph and detail potentially further chipping away at his reputation. Perhaps the biggest risk comes from the court of public opinion.

The Conservatives face two special elections next month which could provide ammunition to Johnson’s critics if the results go against the Tories. And there’s also a cost of living crisis to navigate. 

The prime minister is due to address rank-and-file Tories on Wednesday in an effort to reassure them that he’s still the leader they want heading into the next general election due by 2024.

(Updates with details, context from fifth paragraph)

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