Both major UK parties embark on messy leadership contests

Leave campaigner and Secretary of State for Justice Michael Gove arrives for a cabinet meeting at 10 Downing Street in London, Monday, June 27, 2016. Political turmoil has roiled Britain since the country's vote to leave the European Union, as leaders of the government and opposition parties grapple with the question of how precisely the U.K. will separate from the other 27 nations in the bloc. (AP Photo/Matt Dunham) (The Associated Press)

British Home Secretary Theresa May arrives for a cabinet meeting at 10 Downing Street in London, Monday, June 27, 2016. Political turmoil has roiled Britain since the country's vote to leave the European Union, as leaders of the government and opposition parties grapple with the question of how precisely the U.K. will separate from the other 27 nations in the bloc. (AP Photo/Matt Dunham) (The Associated Press)

Labour Party leader Jeremy Corbyn leaves his home in north London, Wednesday June 29, 2016. Corbyn is expected to face a leadership challenge, but says he won't resign despite a vote of no confidence from his party's lawmakers. (Lauren Hurley / PA via AP) UNITED KINGDOM OUT - NO SALES - NO ARCHIVES (The Associated Press)

Britain's two major parties are preparing for messy leadership contests, setting the stage for parallel competitions that will shape the nature of Britain's exit from the European Union.

Britain's decision to exit from the European Union during Thursday's referendum has thrown both the ruling Conservative and opposition Labour parties into turmoil, with Prime Minister David Cameron pledging to step down and Labour Party chief Jeremy Corbyn expected to face a challenge for the leadership.

Nominations for the Conservative Party close at noon (1100GMT) on Thursday. Ex-London Mayor Boris Johnson, Home Secretary Theresa May and Justice Secretary Michael Gove are among those who've formally announced their intention to replace Cameron.

Corbyn is expected to face a challenge after losing a lopsided no-confidence vote on Tuesday.