Boris Johnson and Jeremy Hunt appear on BBC TV's debate with candidates vying to replace British PM Theresa May. (Photo: Reuters)

Boris Johnson or Jeremy Hunt will be announced as Britain’s new prime minister on July 23, the Conservative Party said on Tuesday.

The party said a postal ballot of the 160,000 or so Conservative Party members to decide who will replace Theresa May as leader would close on July 22 with the winner announced the following day.