Boris Johnson is facing furious criticism following allegations that a Christmas gathering took place inside Number 10 last December.
He yesterday confirmed he will ask the cabinet secretary Simon Case to launch an investigation into the event on 18 December, despite repeated denials it took place.
It has since emerged that a separate event organised by Shaun Bailey’s mayoral campaign took place in the party’s Westminster headquarters on 14 December, while London was in Tier 2 restrictions.
According to the Times, the “raucous” party took place in the HQ’s basement, was attended by Number 10 aides and featured dancing and wine-drinking into the early hours despite indoor social mixing being banned at the time.
A Tory spokesman said: “Senior CCHQ staff became aware of an unauthorised social gathering in the basement of Matthew Parker Street organised by the Bailey campaign on the evening of December 14.
“Formal disciplinary action was taken against the four CCHQ staff who were seconded to the Bailey campaign.”