Theresa May's campaign to take the keys to No 10 has continued to soar ahead of her rivals as she secured the backing of another Cabinet minister just one day before the first round of voting in the contest.
Foreign Secretary Philip Hammond hailed the Home Secretary's "determination in standing up to vested interests" as he threw his support behind her campaign.
It comes as the bitter recriminations continued to flow over Michael Gove's decision to skewer Boris Johnson's leadership bid.
Ben Wallace, who was running the former London mayor's campaign for the top job, said the Justice Secretary was unfit to become prime minister because he was not trustworthy.
Mr Johnson, meanwhile, has claimed Remain supporters have been consumed by the type of "hysteria" last seen after the death of Diana, Princess of Wales, since Britain voted to leave the European Union.
He called for the Government to make a clear statement immediately stating EU nationals already in Britain would not be hit by Brexit and reassuring voters that the "future is very bright indeed".
Free trade with Britain was overwhelmingly in the economic interests of the other members of the bloc and the country could still lead the way on security matters in Europe, he said.
In his column for The Daily Telegraph, he wrote: "There is, among a section of the population, a kind of hysteria, a contagious mourning of the kind that I remember in 1997 after the death of the Princess of Wales."
Mr Johnson studiously failed to mention the events that led to his decision to quit the leadership contest.
But Mr Wallace said that the MP had been "at his home rehearsing for his speech unaware that the press knew before him" that Mr Gove had withdrawn his support and was launching his own bid.
In an article for the Daily Telegraph, the Northern Ireland minister said: "When I was a government whip and Michael was the chief whip, the office leaked like a sieve. Important policy and personnel details made their way to the papers. Michael seems to have an emotional need to gossip, particularly when drink is taken, as it all too often seemed to be.
Mrs May, Mr Gove, Stephen Crabb, Andrea Leadsom and Liam Fox will continue to vie for the support they need from MPs to make it on to the ballot paper ahead of the first round of voting on Tuesday.
The Home Secretary has been backed by a number of senior figures in the party, including Leave campaigner Chris Grayling and Defence Secretary Michael Fallon.
Mrs May has failed to meet the Government's target to cut net migration to the tens of thousands but Mr Hammond insisted she was committed to controlling immigration.
He told the newspaper: "Having worked with Theresa in government for six years, I have seen her determination in standing up to vested interests, her commitment to controlling migration from outside the EU and her tireless work to keep this country safe.
"I know that she has the qualities and the character to take our country forward and, with her quietly determined, down-to-earth style, to reunite us after the referendum, behind a plan to address the deep divisions in our society that it has exposed."