Boris Johnson stopped journalists questioning two of the country’s top coronavirus advisers about the ongoing Dominic Cummings controversy.

At Thursday’s daily briefing, the prime minister said he would not allow scientific advisor Sir Patrick Vallance, and chief medical officer Professor Chris Whitty to answer questions on the row.

More: Groups of six people can meet outside as lockdown is easedIt was the officials’ first appearance since news of the PM’s chief aide journey to County Durham during lockdown, which has seen calls for his resignation.

Earlier on Thursday, Durham Constabulary said Mr Cummings might have committed “a minor breach” of rules when he drove to Barnard Castle.

More: What has your MP said about the Dominic Cummings controversy? Mr Johnson said: “I’ve said quite a lot on this matter already and what I also note is that what Durham police said was that they were going to take no action and that the matter was closed.

“And I intend to draw a line under the matter, as I said yesterday to the Parliamentary Liaison Committee.

“It’s very, very important that our medical officers and scientific advisers do not get dragged into what I think most people would recognise is fundamentally a political argument.”

Both Professor Whitty and Sir Patrick answered that they had no desire to get involved in politics.

Professor Whitty replied: “The desire to not get pulled into politics is far stronger on the part of Sir Patrick and me than it is in the Prime Minister.”

Sir Patrick added: “I’m a civil servant, I’m politically neutral, I don’t want to get involved in politics at all.”