Boris Johnson builds momentum in UK Conservative race

Combo group of ten file photos showing the contenders in the Conservative Party leadership race, with top row from left, Boris Johnson, Dominic Raab, Jeremy Hunt, Rory Stewart, Mark Harper, and bottom row from left, Esther McVey, Matt Hancock, Andrea Leadsom, Michael Gove, Sajid Javid. The official list of ten contenders to replace Prime Minister Theresa May, for the office of Leader of Britain's Conservative Party was released Monday June 10, 2019. (PA via AP)

British Conservative Party lawmaker Boris Johnson leaves his home in London, Tuesday, June 11, 2019. Britain's Conservative Party is holding an election to replace Prime Minister Theresa May, who resigned last week after failing to lead Britain out of the European Union on schedule. Former Foreign Minister Boris Johnson is currently the bookies favorite to replace May. (AP Photo/Frank Augstein)

LONDON – Boris Johnson has solidified his front-runner status in the race to become Britain's next prime minister by gaining backing from leading pro-Brexit lawmakers.

Johnson is promising to lead Britain out of the European Union by Oct. 31, with or without a divorce deal.

Brexit-backing ex-party leader Iain Duncan Smith wrote in Tuesday's Daily Telegraph that Johnson "is the most likely to deliver on the requirement to leave the EU" by that date.

Ten candidates are running to succeed Theresa May as Conservative leader and prime minister. In votes starting Thursday, Conservative lawmakers will narrow the field down to two, who will be put to a vote of party members nationwide.

In a straw poll among some Tory lawmakers on Monday, Johnson received almost double the votes of his nearest rival.