Brexit campaigner and former London mayor Boris Johnson prepares to leave after addressing a press conference in central London on June 30, 2016. Brexit campaigner Boris Johnson said Thursday that he will not stand to succeed Prime Minsiter David Cameron. / AFP PHOTO / LEON NEAL

Boris Johnson, a prominent campaigner for British withdrawal from the European Union, says he will not be a candidate for leadership of Conservative Party

Johnson’s decision means Justice Secretary Michael Gove and Home Secretary Theresa May are front-runners in the race.

They and others will compete to succeed Prime Minister David Cameron.