LONDON (Reuters) -British opposition Labour leader Keir Starmer was cleared by police of breaking COVID-19 lockdown laws on Friday, having said he would quit his job if he was fined.

A day after Prime Minister Boris Johnson announced he would resign following a series of scandals, including repeated lockdown breaches at his Downing Street office, police said Starmer had not broken the regulations.

“I’ve always said no rules were broken when I was in Durham. The police have completed their investigation and agreed: there is no case to answer,” Starmer said on Twitter. “For me, this was always a matter of principle. Honesty and integrity matter.”

Alleged breaches of coronavirus rules became a politically explosive issue for Johnson following the “partygate” scandal that saw the prime minister and scores of others fined for attending illegal gatherings in Downing Street or other government offices.

Starmer faced his own investigation after a video of him emerged drinking beer at a get-together in April 2021 during campaigning for a parliamentary seat election.

Gatherings indoors were banned at the time unless they were essential. Starmer said he had paused for a meal and went back to work later.

Seeking to draw a contrast with Johnson, who had already been fined for breaching lockdown regulations but did not stand down, Starmer had pledged to resign if he was found to have broken the rules. Starmer’s deputy Angela Rayner, who was also at the Durham gathering, had made the same promise.

Durham Police said in a statement there was “no case to answer for a contravention of the regulations, due to the application of an exception, namely reasonably necessary work.

“Accordingly, Durham Constabulary will not be issuing any fixed penalty notices in respect of the gathering and no further action will be taken.”

The revelations of rule-breaking Downing Street parties and Johnson’s subsequent response were a major factor fuelling the discontent against him in his Conservative Party that led to Thursday’s resignation announcement.[nL8N2YP1GC]

(Reporting by Alistair Smout, Kate Holton, Muvija M and Elizabeth Piper; editing by Michael Holden and John Stonestreet)