Boris Johnson has full confidence in Rishi Sunak and the pair are "in lockstep", Number 10 has insisted.

       It comes after Mr Johnson was reported to have made a joke about demoting the Chancellor to Health Secretary, having been angered that a letter to him from Mr Sunak, calling for the easing of travel restrictions, had been briefed to the media.

       Mr Johnson was reported to have said in a meeting last Monday: "Maybe it's time we looked at Rishi as the next Secretary of State for Health. He could potentially do a very good job there."

       However, the Prime Minister's official spokesman said there were no imminent plans for a Cabinet reshuffle.

       "The Prime Minister and the Chancellor have always enjoyed a close and effective working relationship, and will continue to do so," the spokesman said.

       "I think you can see, particularly during the pandemic, they have worked closely together. They have been in lockstep throughout this incredibly challenging period for the country. There are no plans for any reshuffle."

       Kwasi Kwarteng, the Business Secretary, also sought to play down speculation of a reshuffle, saying: "He's doing a fantastic job, he's a very collegiate, excellent Chancellor and I think everyone in the Cabinet, including the Prime Minister, is 100 per cent behind him.”

       He later stressed that Mr Johnson and Mr Sunak were a "good team", telling LBC Radio: "I remember Prime Ministers really having a bad time with their Chancellors, and I think this combination works very well."

       However, Number 10 and Number 11 are understood to be at loggerheads over public spending, with a series of major policy decisions looming in the autumn.

       Earlier this week, Tory MPs told The Telegraph that Mr Johnson would be unwise to sack Mr Sunak, who took over as Chancellor after Sajid Javid resigned in February last year.

       One government figure close to the Chancellor said: "If he demotes him he's only signing his death warrant. There's nobody else as good as Rishi."

       A Tory MP said: "To lose one chancellor may be regarded as a misfortune – to lose two looks like carelessness."

       A recent survey of Tory members put Mr Sunak's approval rating at 74.1 percentage points. The same survey, conducted by Conservative Home, had Mr Johnson at just 3.4 per cent.