According to the Times, an independent investigation into lockdown gatherings at Boris Johnson’s Downing Street office and residence is “excoriating” for the British prime minister and will make things “incredibly difficult” for him.

Sue Gray, a senior civil servant, has been tasked with investigating the events and determining whether they violated Johnson’s lockdown rules. The publication of her report has been halted until the police have completed their own investigation.

Johnson has received one police fine and may face additional charges. In January, an interim version of Gray’s report stated that “serious failures of leadership” resulted in alcohol-fueled parties being held at a time when social mixing was all but prohibited.

According to the Times, the report would be harsh on Johnson, both for attending some of the events and for the office culture in Downing Street.

Johnson has apologized for the gatherings, but claims he was unaware he was violating the rules because he thought he was attending work events. Opposition parties and some of his own lawmakers have urged him to resign.