Britain's Home Secretary Theresa May attends a press conference in London, Britain, June 30, 2016. [Photo/Agencies]

LONDON - British Home Secretary Theresa May remained frontrunner to replace Prime Minister David Cameron Tuesday as one of the five Conservative leadership contenders dropped out of the race and another withdrew hours later.

In a ballot of Conservative members of the Parliament (MPs), ex-Defense Secretary Liam Fox notched up the lowest number of votes, 16, compared to May who won the backing of 165 MPs. He was immediately eliminated from the leadership race.

Just two hours after a vote by Conservative MPs at Westminster had finished, the man who came fourth, Work and Pensions Secretary Stephen Crabb, who won 34 votes, announced he was withdrawing, and backing May.

Of the 330 Conservative MPs in the House of Commons, all voted apart from the Prime Minister whose resignation after the EU referendum triggered the contest.

The result makes it almost certain that May, a Remain supporter in the referendum process, will be one of the two candidates to go forward to the final stage when thousands of party members across the country decide who they want at 10 Downing Street.

Pro-leave Andrea Leadsom, the energy and climate change minister, came second in Tuesday's ballot, with 66 votes, followed by Justice Secretary Michael Gove, who won 48 votes.

A second ballot Thursday will decide which two of the three will go to a national ballot of all Conservative Party members.

May is virtually guaranteed a place, meaning Thursday vote will effectively decide whether her challenger will be Leadsom or Gove.

Gove has faced criticism from many within the party for treachery after he decided to stand, knowing that former mayor of London Boris Johnson had already set his sights on moving to 10 Downing Street.