Boris Johnson continued to stand by his senior aide Dominic Cummings and insisted it is time to “move on” from the alleged lockdown breaches despite mounting Tory anger and plummeting poll ratings.

The Prime Minister rejected a call on Wednesday for Cabinet Secretary Sir Mark Sedwill to investigate Mr Cummings’ actions during the height of the coronavirus outbreak.

Mr Cummings drove from London to Durham to isolate with his family during the lockdown, and says he subsequently took a trip to Barnard Castle to see if he was fit enough to drive before returning to the capital.

At least 35 Tory MPs have called for Mr Cummings’ departure, while senior minister Penny Mordaunt admitted there were “inconsistencies” in his account and that “there is no doubt he took risks”.

Mr Johnson came under intense questioning in an appearance before the Commons Liaison Committee of senior MPs, during which he announced NHS England’s test and trace programme would be resumed the following day.

“Quite frankly I’m not certain – right now – that an inquiry into that matter is a very good use of official time,” the PM said. “We are working flat out on coronavirus.”

He said he was “deeply sorry for all the hurt and pain and anxiety that people have been going through throughout this period”, but repeatedly insisted it was now time to “move on”.

He argued during the appearance before the committee, comprised of the chairmen and women of Commons select committees, that the public wanted politicians to focus on “uniting our message” and “focusing on their needs”.

Mr Johnson also admitted it had been a “very frustrating episode”, which he sought to dismiss as a “political ding dong” with inaccuracies but he refused to state which aspects of the allegations were untrue.

And he used his appearance at the committee to announce that NHS England’s test and trace system would be up and running from Thursday.

The scheme will see people who have been in contact with someone who tests positive for coronavirus ordered to self-isolate for 14 days.

Cumulative deaths involving Covid-19 in the UK
(PA Graphics)

Meanwhile, the toll of deaths linked to the virus rose to almost 48,000.

Mr Johnson’s defence of Mr Cummings came after a minister quit in protest and the number of Tory MPs to publicly call for the controversial aide to leave his post continued to grow.

Ms Mordaunt, who is Paymaster General, said in an email to constituents that it was clear the fallout had “undermined key public health messages”, adding: “I deeply regret this and am very sorry for it.”

“Despite Mr Cummings’ statement yesterday, I am personally still not clear of the facts. There are some inconsistencies in his account of events and the reasons behind it. I am not clear about when he would have been symptomatic and on what dates he should have been in isolation. Or whether it was appropriate he drove home at the time he did,” she also wrote.

A YouGov survey for The Times showed the Conservative lead over Labour had been cut by nine points during the Cummings saga – the biggest drop since 2010 – as support for the Government fell four points to 44% with Labour rising five points to 38%.

In an indication of the difficulties Mr Cummings’ actions are causing at the top of Government, ministers were forced to deny that a review was being launched into fines issued to other people travelling with their families.

Health Secretary Matt Hancock used Tuesday’s Downing Street press conference to indicate he would consult the Treasury and “look at it”.

But on Wednesday morning, Communities Secretary Robert Jenrick said “there isn’t going to be a formal review” and the issuing of fines was a matter for the police.

He defended Mr Cummings’ actions and said people could “exercise a degree of personal judgment” in following lockdown laws.

Coronavirus-related deaths in hospitals in England
(PA Graphics)

“If there are no other options, if you don’t have ready access to childcare, then you can do as Dominic Cummings chose to do,” Mr Jenrick told BBC Radio 4’s Today programme.

“The guidelines say that you must do your best, but they appreciate that family life poses particular challenges and in order to protect children you are able to exercise a degree of personal judgment.”

Tory MPs and scientists advising ministers have warned that Mr Cummings’ actions risk undermining respect for the restrictions which have helped curb the spread of the virus.

HEALTH Coronavirus
(PA Graphics)

In other developments:

– The PM’s sister Rachel Johnson told ITV’s Good Morning Britain that if she were in Mr Cummings’ position she would apologise and admit she “messed up”

– Andy Burnham, the Mayor of Greater Manchester, poured cold water over the Government plans to use “local lockdowns” to fight flare-ups of coronavirus

– Weston General Hospital in North Somerset closed to new admissions to “avoid being the cause of an outbreak” after tests revealed a number of staff with no symptoms had coronavirus

– Education Minister Nick Gibb said it was “difficult to say” whether the Government’s ambition to get all primary school children in England back in class before the summer holidays will come to fruition.