"He has clearly broken the rules, he may have broken the law," London Mayor Sadiq Khan told ITV News London.
Former London mayoral candidate Shaun Bailey has stood down from his role as chair of the London Assembly's policing body after it emerged he went to a Christmas party which broke Covid rules.
The Conservative London Assembly member went to the Christmas gathering organised by his campaign team at Party headquarters last December when London was in Tier 2 and indoor mixing between households was banned.
Mr Bailey resigned from the role shortly before The Mirror published a photograph of him and other staff at the party.
The image showed 24 people with drinks, and buffet food laid out.
Mr Bailey's team called the party a "serious error of judgement" and fully accepted the party should not have taken place.
The Tories previously admitted the party had taken place on December 14, when London was in Tier 2 restrictions, and said that staff had been disciplined.
"There was a party-culture in Downing Street" last Christmas, says Political Editor Robert Peston, and warns more photos could come out
And the GLA Conservatives confirmed on Tuesday that Mr Bailey had stepped back from the role.
In a statement, they said: “Shaun Bailey AM has today stood aside as chairman of the London Assembly’s Police and Crime Committee.
“He does not want an unauthorised social gathering involving some former members of the London mayoral campaign team last December to distract from the committee’s important work holding the Mayor of London to account.
“He will continue to speak up for Londoners who no longer feel safe in our city and push for a strategy to tackle the disproportionate level of crime in London’s black community.”
A Tory spokesman previously said: “Senior CCHQ (Conservative Campaign Headquarters) 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.”
Speaking to ITV News London mayor Sadiq Khan said Shaun Bailey had "done the right thing" in standing down from his role.
"He has clearly broken the rules, he may have broken the law," Mr Khan said.
"He has set an example for the Prime Minister and those in government - those who are rule makers shouldn't be rule breakers.
It breaks down the trust and confidence the public needs to have with those of us in positions of power and influence," he added.