Sir Graham is facing an election against South Derbyshire MP for the chairmanship of the influential 1922 Committee. The position is meant to be one which acts as a critical friend to the party leadership and represents the concerns of backbenchers to ministers.

       But it is understood that Boris Johnson has grown annoyed with Sir Graham’s opposition to lockdown and questioning over the covid policy’s damaging effects on the economy and wider public and mental health.

       He has been a prominent supporter of the lockdown sceptic group of around 70 Tory MPs on the Covid Research Group chaired by Mark Harper and Steve Baker.

       Concerns have been raised that a “soft whipping operation” has been taking place to ensure that the more supportive Ms Wheeler wins the vote which will probably take place in September.

       One Tory backbencher told the Sunday Express: “It’s a lot closer than Graham perhaps realises. We need to be worried.”

       Another said: “Heather believes she has the numbers to win.”

       A third MP said: “We really do not want a 22 chair who will just parrot the government line. We need somebody like Graham who is willing to stand up to them when necessary.”

       A source close to Sir Graham said that “he thinks it is ok but he is still working hard to secure the support of colleagues.”