Liz Truss has won the backing of former Tory leadership rival Tom Tugendhat.
In a major boost for the Foreign Secretary’s campaign, Mr Tugendhat wrote in The Times that her plans for vast tax cuts are “founded on true Conservative principles”.
The chairman of the Foreign Affairs Select Committee also criticised Rishi Sunak’s tightening of fiscal policy, saying it is “not right” that the tax burden should be rising when people are heading into winter with “dread”.
He wrote that Ms Truss was the only candidate ready to become prime minister and unite the party.
“These debates have shown a different side of both candidates. Only one has convinced me she’s ready....I’m backing Liz.”
His endorsement is important as he is popular among Conservative Party members and a senior figure in the One Nation group of centrist Tory MPs.
It is another blow to Mr Sunak, after Defence Secretary Ben Wallace also came out in support of Ms Truss.
His support comes hours after Mr Sunak was grilled by Channel 4’s Andrew Neil about his economic plans.