When asked by Labour MP Meg Hillier, whether he had seen the evidence to “prove” that some of the allegations made against Cummings were false, Johnson replied: “If it pleases you, I will say yes I did.”

Then asked if the cabinet secretary could see the evidence or if it could be published, Boris Johnson replied that he would not be doing his job if he “shuffled the problem into the hands of officials.”

Later during the session, Darren Jones MP asked Johnson to clarify which allegations specifically he thought against Cummings were false, to which Johnson replied he had nothing further to add on what he previously said.

Pressed on the matter again he replied: “I don’t want to go back into that Darren, as I’ve said repeatedly to other distinguished members of this committee, it is my strong belief that although I understand people’s frustrations, people’s indignation with the whole business, believe me I do, I think what the country wants is for us to be focusing on how to go forward on the test and trace scheme that we’re announcing today, on how we’re going to protect their jobs, their livelihoods and defeat this virus.”

Johnson’s refusal to share the evidence came as MPs questioned him over his handling of the political storm involving his top aide during a meeting of the House of Commons Liaison Committee chaired by Sir Bernard Jenkin.

The prime minister continued to insist that Cummings acted “responsibly, legally and with integrity” as he faced mounting pressure to dismiss him over his 264 mile trip from his London property to his parent’s home in Durham on the night of March 27, at a time when he suspected that both he and his wife had COVID-19 symptoms.

At a press conference Cummings told reporters he was concerned that if both he and his wife became ill, there was nobody in London they could “reasonably ask to look after our child and expose themselves to COVID” so made the trip to his parent’s.

Johnson had imposed nationwide lockdown restrictions on March 23, telling the rest of the country they “must stay at home” and that they could not meet family or friends that they do not live with.

Those with COVID-19 symptoms were told to self-isolate for seven days, while members of their household had to stay indoors for at least 14 days.

Although ministers insisted insisted that Cummings stayed put when he went to Durham,with Chancellor Rishi Sunak tweeting: “Taking care of your wife and young child is justifiable and reasonable, trying to score political points over it isn’t”, subsequent witnesses stepped forward to say that this wasn’t the case and that Cummings had made a 60-mile round trip to a beauty spot, the Guardian and the Mirror reported.

Cummings was spotted in Barnard Castle, a market town in County Durham in the northeast of England, on April 12, which he has admitted.

He says that the fact it was his wife’s birthday on the same day was purely a coincidence.

It is also alleged by the newspapers that he was back in Durham on April 19, though Cummings says that this is false and can be proven with information on his mobile phone.

This was just days after he was photographed in London having recovered from the virus, suggesting that following his first trip across the country at the end of March he had made a second journey from the capital to north-east England.

During the questioning at the Liaison Committee, Labour MP Yvette Cooper said it was “extremely surprising” the prime minister wouldn’t provide the evidence he says he has seen to prove that some of the allegations against Cummings were false to the cabinet secretary or have any independent verification.

In a sign of increasing frustration within the ranks of his own party, Conservative MP Simon Hoare told Johnson that, if his inbox was anything to go by, the nation will be “far less energetic” about obeying future restrictions as “a direct result of the activities of your senior adviser”.

The Prime Minister replied: “I don’t think that’s true about how the British people will respond to the next phases, to how to work the test and trace system, I don’t think that’s how they responded at all throughout the crisis.

“If, just suppose for a second that you were right, which I don’t accept, all the more reason now for us to be consistent and clear in our message driving those key messages.”

A junior minister has already resigned over the prime minister’s refusal to sack his adviser.

Douglas Ross, the minister for Scotland, announced on Twitter: “I haven’t commented publicly on the situation with Dominic Cummings as I have waited to hear the full details.

“I welcome the statement to clarify matters, but there remains aspects of the explanation which I have trouble with. As a result I have resigned as a government minister.”

Opinion polls published earlier this week, suggested that Johnson had lost popularity among the public following the political storm.

According to data by polling group Savanta ComRes, Prime Minister Boris Johnson’s approval rating has dropped by 20 points in four days following the discovery Cummings had broken lockdown rules.

Johnson’s approval dropped to -1 percent, which is down from the +19 percent he enjoyed just five days ago.