More fines should not increase pressure on Prime Minister Boris Johnson to resign, a Cabinet minister has said.

Welsh Secretary Simon Hart took up the defence of Mr Johnson on Thursday morning after a bruising 24 hours, which saw the Prime Minister being hit by the resignation of a justice minister who warned the scale and nature of breaches of coronavirus rules in Downing Street were inconsistent with the rule of law.

After police issued fixed-penalty notices to the Prime Minister and Chancellor Rishi Sunak over a birthday party held for Mr Johnson in No 10 in June 2020, Conservative MPs Nigel Mills and Craig Whittaker also said the position of the PM is untenable.

But Mr Hart told LBC Radio that Mr Johnson should not resign even if he is issued with more fines, as he claimed: “I don’t think fixed-penalty notices should include automatic sacking for people who happen to be in public life.”

I think the correct sanction is a fixed-penalty notice. I don't think fixed-penalty notices should include automatic sacking for people who happen to be in public life

Mr Johnson has not ruled out the prospect he could be fined again for further events, reportedly having attended six of the 12 under investigation.

The Welsh Secretary told LBC presenter Nick Ferrari: “I think there are also quite a lot of people who are looking at this as one problem, if you like, because all these things allegedly happened around the same time.

“They were entered into, as it turns out, in a sort of misjudged way, but at the time and as reported, they were not considered to be offences, so I don’t know, for me, it doesn’t make a lot of difference whether it’s one or three.

“Others will take a different view, but as I say, I think the correct sanction is a fixed-penalty notice. I don’t think fixed-penalty notices should include automatic sacking for people who happen to be in public life and that just happens to be my rather liberal view.”

When asked if he would hold the same view even if half a dozen fines are issued, Mr Hart said: “Frankly, the principles are the same, whether it’s one or five. Some people will take a view that there’s a sort of ceiling. I personally don’t understand the logic of that, but others, as I say, on this may take a different view.”

Mr Hart also defended Mr Johnson’s breach of lockdown regulations, arguing his birthday gathering at Downing Street had been reported at the time in a story written by Times journalist Steven Swinford but “nobody thought that it was remotely unusual or unlawful”.

He explained on LBC Radio: “What I find odd, back in June when it (the story) was written, absolutely nobody picked up on it.

“The Times newsroom, Steven Swinford himself, an experienced journalist, the police, commentators, opposition members of Parliament, nobody thought that it was remotely unusual or unlawful that that should have happened.”

Mr Hart’s comments are in stark contrast to the ones of Lord Wolfson, a justice minister since 2020, who said in his resignation letter to Mr Johnson that he has come to the “inevitable conclusion that there was repeated rule-breaking, and breaches of the criminal law, in Downing Street”.

He concluded he had no option but to resign considering “my ministerial and professional obligations to support and uphold the rule of law”.

The decision heaped pressure on Dominic Raab, whose Labour shadow Steve Reed pointed out as Justice Secretary is “constitutionally charged with upholding the law but is instead condoning law-breaking” by backing Mr Johnson.

Mr Raab described Lord Wolfson as a “world-class lawyer” whose “wisdom and intellect will be sorely missed” in Government.

Mr Johnson wrote to the peer saying he was “sorry to receive” the resignation, while praising his “years of legal experience”.

On Wednesday, Mr Mills became the first Tory backbencher to publicly call for Mr Johnson to fall on his sword since the fines were issued.

The MP for Amber Valley, in Derbyshire, told the PA news agency that Mr Johnson’s position is untenable, saying: “I think for a Prime Minister in office to be given a fine and accept it and pay it for breaking the laws that he introduced… is just an impossible position.”

Mr Whittaker, the MP for the West Yorkshire constituency of Calder Valley, called for both the Prime Minister and Mr Sunak to resign in response to questions from voters, but, unlike Mr Mills, he said he would not be submitting a letter to the 1922 Committee of backbench Tories.

He argued the Prime Minister would win the vote, which would detract from the Government’s “day-to-day” business.

Both Mr Johnson and Mr Sunak – and the Prime Minister’s wife Carrie, who was also fined over the party in the Cabinet Room – apologised on Tuesday and confirmed they had paid the fines.

Mr Hart is not the only political figure to have publicly defended Mr Johnson.

Multiple Tory MPs and Cabinet ministers have expressed their backing for the Prime Minister, pointing to his support for Ukraine in response to Vladimir Putin’s invasion.

On Wednesday, Transport Secretary Grant Shapps insisted the Prime Minister had made a mistake but did not knowingly break the law.

One who was publicly quiet over the scandal was Home Secretary Priti Patel, but a Home Office source said Mr Johnson has her “full support”.

It was argued it was difficult for Home Office ministers to comment on ongoing police investigations.