Theresa May will remain Prime Minister until at least 2020 and could even fight another general election, one of her Cabinet colleagues has predicted.

Chris Grayling, the Transport Secretary, is confident Mrs May will fight on once Brexit has been achieved in March 2019 because she “commands the overwhelming support of the Conservative Party”.

If he is proved right, it increases the chances of a fresh face in the party emerging from the backbenches to succeed her, as David Cameron did in 2005, just four years after becoming an MP.

As Mrs May’s campaign manager during her successful 2016 leadership bid, Mr Grayling is one of her most loyal Cabinet ministers.