A furious Boris Johnson is reported to have told his allies to back "anyone but Rishi Sunak" in the race to choose his successor as Prime Minister, according to a report in The Times newspaper.

According to the report, caretaker Prime Minister Johnson and his camp are running an "anyone but Rishi" hidden campaign as they feel betrayed over the former Chancellor's resignation which precipitated his exit from 10 Downing Street.

"The whole No.10 team hates Rishi. It's personal. It's vitriolic. They don't blame Saj [Sajid Javid] for bringing him down. They blame Rishi. They think he was planning this for months," the leading newspaper quoted a source as saying.

Johnson, who resigned as the leader of the ruling Conservative Party on July 7, has said he will not endorse any leadership candidates or publicly intervene in the contes. However, he is believed to have held conversations with defeated candidates in the race for Tory leadership and urged that Sunak should not become the prime minister.

A source close to one of the conversations said the current prime minister appeared most keen on Liz Truss, the foreign secretary, endorsed by his fiercest cabinet allies, Jacob Rees-Mogg and Nadine Dorries.

Johnson is also reportedly open to Penny Mordaunt, the junior trade minister, succeeding him instead of Sunak.

Sunak, who was the winner of the first two rounds of voting by Tory members of Parliament, will appear for a series of televised debates over the weekend with his remaining opponents — Trade Minister Penny Mordaunt, Foreign Secretary Liz Truss, former minister Kemi Badenoch

“Polling is as yet fluid. Most polls have shown Sunak favoured both by his party and by the wider British public. This could answer any doubts Conservative members might have as to whether the wider electorate will favour a member of an Asian immigrant family. Indeed it suggests that the nation is eager for precisely the maturity of judgment it urgently needs,” according to Guardian columnist Simon Jenkins.

“Of Sunak’s rivals, both Hunt and Penny Mordaunt have failed to capture the political imagination of the country, while Liz Truss has shown herself startlingly lightweight in her public pronouncements. Her attempt to portray herself as a new Thatcher and as the beacon of the party’s right wing is ludicrous. It is hard to recall her making a thoughtful speech in her life. She lives and breathes cliché,” Jenkins wrote in his article.

Also read: Rishi Sunak among top eight contenders as competitors drop out of UK’s Prime Ministerial race