Boris Johnson refused to accept coronavirus lockdown laws were broken at the heart of his government despite the Metropolitan Police’s decision to issue 20 fines over rule-breaking parties.

The Prime Minister’s position puts him at odds with his deputy, Dominic Raab, who said the Met’s decision to start sending out fixed penalty notices (FPNs) meant it was clear that the law was breached.

Mr Johnson ducked questions about his own future as he was challenged by MPs about the partygate scandal.

An initial round of 20 FPNs have been issued as part of Scotland Yard’s investigation into a series of gatherings in 2020 and 2021.

Mr Raab, the Justice Secretary and a lawyer, said it was “clear there were breaches of the law”.

“Clearly there were breaches of the regulations,” he told BBC Radio 4’s Today programme.

“That is the only thing that can warrant the 20 fixed penalty notices. That must follow.”

At the Liaison Committee, SNP MP Pete Wishart asked Mr Johnson to accept “there has been criminality committed”, given Scotland Yard’s decision to issue FPNs.

The Prime Minister said: “I have been, I hope, very frank with the House about where I think we have gone wrong and the things that I regret, that I apologise for.

“But there is an ongoing investigation… I am going to camp pretty firmly on my position.”

He added: “I won’t give a running commentary on an ongoing investigation.”

Mr Johnson sidestepped questions about whether he would be “toast” if he was issued with an FPN or if he would resign if he broke the Ministerial Code.

“I think you’re just going to have to hold your horses and wait until the conclusion of the investigation when there will be a lot more clarity,” Mr Johnson said.

He indicated he had not been one of the people issued with a fixed penalty notice but “I’m sure you would know if I were”.

Earlier at Prime Minister’s Questions, Sir Keir Starmer suggested Mr Johnson should resign for misleading the House by denying the allegations of wrongdoing at the parties during England’s coronavirus lockdowns.

“He told the House no rules were broken in Downing Street during lockdown. The police have now concluded there was widespread criminality,” the Labour leader and former director of public prosecutions said.

“The Ministerial Code says that ministers who knowingly mislead the House should resign. Why is he still here?”

The Prime Minister said: “Of course the Met, the investigators, must get on with their job, but in the meantime… we are going to get on with our job.

“That means tackling the cost of living, addressing the UK’s energy supply and improving education.

“That’s what we’re focusing on and I think that’s what the people in this country want us to focus on.”

The FPNs being issued by the Met relate to investigations into a series of around a dozen events in Downing Street and Whitehall while England was subject to coronavirus lockdown restrictions – including one in the Prime Minister’s flat.

Although Mr Johnson is not expected to be among the first group to be hit with fines, the Met have indicated they expect to issue more fixed penalty notices as their investigations continue.

Sir Keir said there are “only two possible explanations” for Mr Johnson’s position: “Either he’s trashing the Ministerial Code or he’s claiming he was repeatedly lied to by his own advisers, that he didn’t know what was going on in his own house and his own office.

“Come off it.

“He really does think it’s one rule for him and another rule for everyone else, that he can pass off criminality in his office and ask others to follow the law.”

During a round of Wednesday morning broadcast interviews Mr Raab insisted Mr Johnson had not been aware of the “infractions” when he repeatedly told MPs there had not been any breach of the law.

The Prime Minister had been speaking to the best of his knowledge at the time, Mr Raab said, and had not deliberately lied – even though he had been at some of the events which were under investigation.

“I think it is rather different to say that he lied, which suggests that he was deliberately misleading. The PM has not to date been issued with a fixed penalty notice,” Mr Raab told BBC Breakfast.

“Clearly we had the investigations because of the claims, the assertions that were made, which it was right to follow up, and it is clear there were breaches of the law.

“But to jump from that to say the Prime Minister deliberately misled Parliament rather than answering to the best of his ability is just not right.”