Boris Johnson is under growing pressure to fire top aide Dominic Cummings as 19 Conservative MPs, bishops and NHS staff called for his resignation over suggestions he broke lockdown rules.
The prime minister told the nation on Sunday Mr Cummings acted "responsibly, legally and with integrity" after his chief adviser admitted travelling 260 miles to his parents in Durham for childcare support after his wife displayed coronavirus symptoms.
Members of the public also claimed to have seen him in Barnard Castle, a picturesque town 30 miles from Durham, then again in the county after he had returned to London.
So far, 19 Conservative MPs have called for Mr Cummings' resignation, including former ministers Steve Baker, Caroline Nokes and Tim Loughton.
Former minister Paul Maynard said: "It is a classic case of 'do as I say, not as I do' - and it is not as if he was unfamiliar with guidance he himself helped draw up.
"It seems to me to be utterly indefensible and his position wholly untenable."
The MPs join a growing line of high-profile figures calling for Mr Cummings to listen to his own advice instead of flouting the rules.
Church of England bishops accused the PM of treating people "as mugs" and with "no respect" after loyally sticking by his chief aide.
The Rt Revd Nick Baines, Bishop of Leeds, tweeted: "The question now is: do we accept being lied to, patronised and treated by a PM as mugs?"
And an NHS doctor has threatened to resign by the end of the week if Mr Cummings has not done so by then - and said he thinks many of his fellow NHS workers will happily do the same.
Dr Dominic Pimenta, a cardiology registrar, tweeted a picture of himself wearing personal protective equipment (PPE), saying: "Frankly, Cummings spits in the face of all our efforts, the whole NHS. If he doesn't resign, I will."
Durham County Council's Liberal Democrat opposition leader Amanda Hopgood said she had written to Durham police's chief constable Jo Farrell asking for an investigation into Mr Cummings after "a number" of locals reported seeing him in the county.
Durham's acting police and crime commissioner Steve White has also asked the force to "establish the facts concerning any potential breach of the law".
Scientists from the Scientific Pandemic Influenza Group on Behaviours, who have been advising the government, said by backing Mr Cummings, Mr Johnson had "trashed" their advice on how to deal with the pandemic.
Labour leader Sir Keir Starmer insists he would have sacked Mr Cummings if he was prime minister, and that Mr Johnson is treating the British people with "contempt" by refusing to get rid of his chief adviser.
Scottish First Minister and SNP leader Nicola Sturgeon said Mr Cummings should either resign or be sacked, pointing out she had had to accept the resignation of Scotland's chief medical officer adviser Catherine Calderwood last month for her own lockdown breach.
"I know it is tough to lose a trusted adviser at the height of crisis, but when it's a choice of that or integrity of vital public health advice, the latter must come first," Ms Sturgeon tweeted.
"That's the judgement I and, to her credit, Catherine Calderwood reached. PM and Cummings should do likewise."
Education Secretary Gavin Williamson told Sky News on Monday Mr Cummings made "absolutely clear" to the prime minister that "at no stage did he break the law or break the rules" and Mr Johnson "agreed with the assessment".
Twice challenged to deny that the under-fire adviser travelled to Barnard Castle, he did not do so directly, but repeated the aide had "operated within the rules".
Mr Cummings' parents, Robert and Morag, have come to their son's defence, with his mother saying the family had been grieving after her brother, Lord Justice Laws, who died on 5 April after contracting COVID-19 in hospital.
An unnamed neighbour told the Mirror and the Guardian they saw Mr Cummings on the day his uncle died - and the PM was admitted to hospital with coronavirus symptoms - in his parents' garden with Abba's Dancing Queen playing loudly.
His father said he was "disgusted" at the way the press had treated his son since news of his travels broke.
The government defended Mr Cummings by saying the first trip - which he has admitted to - was necessary because both he and his wife had coronavirus symptoms and they needed family to help with childcare for their four-year-old son.