The Duke of Cambridge’s private secretary has been given a leading role in Downing Street to help develop and implement the Government’s response to Covid-19.

Simon Case, who is on a secondment to Whitehall, is now permanent secretary at 10 Downing Street following almost two years working as William’s right hand man.

The Prime Minister’s official spokesman said: “Simon is working on the coronavirus response in No 10 as a permanent secretary. Simon is with us temporarily from the Royal household.”

“He is specifically co-ordinating the coronavirus response. Coronavirus is obviously a very significant piece of cross-Government work.”

Mr Case will report to Cabinet Secretary Sir Mark Sedwill, the spokesman said.

William’s private secretary, a former career civil servant, had served as principal private secretary to David Cameron when he was Prime Minister and his successor Theresa May during 2015-17.

Before he began working for William, in July 2018, he was Director General Northern Ireland and Ireland in the Department for Exiting the EU.

The duration of Mr Case’s secondment will be agreed between the Cabinet Office and the Royal Household.

But the duke is likely to be without his private secretary until the coronavirus outbreak is well under control.