Video report by ITV News Political Correspondent Carl Dinnen
Boris Johnson has attempted to downplay allegations against his advisor Dominic Cummings, describing the row over his trip from London to Durham as a "political ding dong" and refusing to order an inquiry into the alleged lockdown breach.
The prime minister said many of the allegations against Mr Cummings were "totally false" but declined to provide any evidence to prove his claims.
Mr Johnson was facing questions from the Liaison Committee after his chief aide Mr Cummings made a 260-mile trip to his parents' farm in Durham with his family, while his wife had coronavirus symptoms during lockdown.
The 48-year-old said he had made the trip so he could be closer to childcare should he or his wife become incapacitated by the illness.
Mr Cummings has denied wrongdoing, saying he believed he acted "reasonably" and within the law by making the journey.
Asked by Committee Chair Sir Bernard Jenkin why an inquiry had not been ordered into Mr Cummings' journey, the PM said he is "not certain" looking into the matter would "be a very good use of official time".
ITV Political Editor Robert Peston analyses the latest developments
Mr Johnson said "a lot of what was written and said" about Mr Cummings' trip "wasn't correct", however when asked by MP Meg Hillier if he would provide evidence to the Cabinet Secretary, Mr Johnson declined.
"I think actually that it would not be doing my job if I were not to shuffle this problem into the hands of officials," he said.
He acknowledged the "great political interest" in the story and said he could "understand public indignation" but said "it would be much better if we could now move on and focus on the next steps" of the fight against coronavirus.
The prime minister was accused of causing confusion over the government's lockdown message by his defence of Mr Cummings.
Labour’s Yvette Cooper, citing a survey by Mumsnet, said a quarter of parents didn’t have access to local childcare when they had Covid-19 and were “in exactly the same circumstances as Dominic Cummings”
She said a third of those parents told the survey they'd be "more likely to break the rules now" following the news.
She asked if the prime minister now wanted people to follow advice from health experts, who say "stay at home, unless theres a risk to life”.
Or, she asked, "in the words of Robert Jenrick this morning; 'if you don’t have ready access to childcare then you can do as Dominic Cummings did', which is it?”
Responding the PM said: "If you have exceptional problems with childcare then that may cause you to vary your arrangements and that’s clear."
Ms Cooper, unhappy with the answer, accused Mr Johnson of "ducking" questions, and said he was doing so to "protect" his advisor.
She said he was "putting political concerns ahead of clear public health messages", an accusation he denied.
"The reason you sent all of your ministers out to say fudgey things and unclear things is because you are trying not to incriminate Dominic Cummings and you don’t want to apologise for him," she added.
He hit back, urging MPs to "lay aside party political points scoring and put national interest first".
Earlier in the Committee, Mr Johnson was asked by SNP Pete Wishart to apologise on Mr Cummings' behalf, however he appeared to decline.
He said: "I am sorry for the pain, as I’ve said, the anguish and the heartbreak of so many people in this country."
Asked if he believed Mr Cummings' behaviour had been a distraction, Mr Johnson disagreed, saying the public want “us to focus on them and their needs rather than on a political ding dong about what one advisor may or may not have done".
The prime minister said Mr Cummings was allowed to give his own press conference, so the public could "understand what I had understood myself previously".
A poll, conducted after the news of Mr Cummings' trip broke, showed some 59% of Britons think he should resign.
And at least 40 Tory MPs have now called for his resignation, including former Scotland minister Douglas Ross, who resigned over the government's response to the news.
Backbench Tories to call for him to resign include Mark Harper, Sir Roger Gale and Steve Baker.
The prime minister's appearance at the Committee was arranged last week after he was invited by Chair Sir Bernard Jenkin.
Sir Bernard's appointment to the committee's chairmanship - made following a recommendation from Number 10 - has been criticised by MPs who view him as too close to the prime minister.
Ahead of the prime minister's appearance, senior Tories Tom Tugendhat and Tobias Ellwood were told they had not been selected to attend.
Tory MPs have indicated to ITV News Political Correspondent Paul Brand that the exclusions - ordered by Sir Bernard - had been made to give the PM an "easy ride".
Watch the full Commons Liaison Committee:
The Liaison Committee is the only Commons committee able to question the prime minister, and it gets to do so usually three times a year.
This is Mr Johnson's first appearance at the committee in 10 months as prime minister - he has cancelled three previously arranged appearances.
At Wednesday's appearance he refused to commit to another appearance before the summer.
The Committee is made up of the chairs of the House of Commons Select Committee.