Johnson wins key Brexit backing in UK leadership race

British leadership favourite Boris Johnson won the endorsement of a key Brexit-backing rival on Wednesday despite accusations he was softening his rhetoric on leaving the EU.

Ahead of another round of voting among Conservative MPs, former Brexit secretary Dominic Raab said Johnson was the "only candidate" who would take Britain out of the European Union as planned on October 31.

On Tuesday, Raab was eliminated from the contest to replace Theresa May as the leader of the governing Conservative Party and therefore as prime minister, leaving five candidates standing.

One of them will be eliminated in another ballot later Wednesday, before further votes on Thursday to whittle the field down to a final pair.

Former foreign minister Johnson is leading the pack after securing the support of 126 of the 313 Conservative MPs in Tuesday's ballot.

A figurehead of the 2016 referendum campaign for Brexit, he insists there must be no more delays to Britain's EU exit, after May postponed it twice.

During a television debate on Tuesday, watched by an average 5.3 million viewers, Johnson said further delay would cause a "catastrophic loss of confidence in politics".

But he declined to guarantee this would happen -- and one of his main rivals, Foreign Secretary Jeremy Hunt, suggested afterwards that his position was not clear. "I am not entirely sure what he believes on this," Hunt told BBC radio.

Hunt came second in Tuesday's ballot with 46 votes, followed by Environment Secretary Michael Gove -- another leader of the 2016 Brexit campaign -- on 41.

International Development Secretary Rory Stewart, the only candidate to rule out leaving the EU with no deal, continued his unlikely progress with 37 votes.

Sajid Javid, Britain's first Muslim interior minister, scraped through with 33 votes -- the minimum to avoid elimination -- while Raab fell short with 30.

Raab was viewed as the candidate with the most hardline policy on Brexit, even suggesting he could suspend the session of parliament if it tried to block "no deal". Stewart said Wednesday that he was in talks with Gove about joining forces.

Tuesday's BBC debate was the first of the campaign to feature Johnson, who dodged a previous one on Sunday and has kept his public and media appearances to a minimum.

But none of the candidates made any major headway or gaffes, and Johnson remains the runaway favourite.

Opposition leaders on Wednesday targeted the front-runner's past comments, with the Scottish National Party's leader in parliament Ian Blackford telling MPs: "not only is the member racist, he is stoking division in communities."