The new leader of Britain's Conservative party Boris Johnson arrives at his office in central London, Tuesday, July 23, 2019. File photo: Yui Mok/PA via AP.

LONDON —  Former foreign secretary Boris Johnson on Tuesday won the race to be the leader of the UK's Conservative Party and will become the country's next prime minister.

Johnson won about two-thirds of the votes by Conservative party members in a run-off with Foreign Secretary Jeremy Hunt, putting him one step - and one day - away from becoming Britain's new leader.

Cheryl Gillan, co-chair of the election committee, told hundreds of party members and reporters that Johnson had been elected the new leader of the Conservative Party with immediate effect, following a ballot of the 160,000 Conservative members.

Johnson replaces Theresa May, who announced her resignation last month, and will officially become prime minister on Wednesday.

May stepped down after Britain's Parliament repeatedly rejected the withdrawal agreement she struck with the 28-nation bloc. 

Johnson insists he can get the EU to renegotiate — something the bloc insists it will not do. If not, he says Britain must leave the EU on Halloween, "come what may."

* This is a developing story

AP and dpa