Tories vote for final pair in race to be Brexit PM

Interior minister Theresa May is the frontrunner in the leadership race, but two Brexit campaigners are battling to be her opponent in the final contest, which will be decided by 150,000 party members and due to be announced on September 9.

The winner, who will become prime minister without need for a general election, will have the task of extricating Britain from its 43-year membership of the European Union following the seismic vote in last month's referendum.

EU leaders have warned against dragging out the process, a point pressed by Christine Lagarde, managing director of the International Monetary Fund, in an interview with AFP in Washington.

"The key word about this Brexit affair is uncertainty and the longer the uncertainty, the higher the risk," she said.

"The sooner they can resolve their timeline and the terms of their departure the better for all. It needs to be predictable as soon as possible."

Some Conservative MPs agree -- about 30 have signed a letter organised by former party chairman Grant Shapps calling for a new leader to be installed by the end of July.

The shock result of the June 23 referendum prompted Cameron to resign and sent global stock markets and the value of the pound plunging.

London's FTSE 100 index has recovered but the Bank of England warned this week that the feared risks to financial stability were starting to materialise.

Aberdeen Asset Management on Thursday became the seventh financial group to order a temporary suspension on redemptions from UK property funds after investors rushed to withdraw investments.

Lagarde said Brexit was a "major downside risk" to the world but played down the likelihood of a global recession, saying: "The immediate effects will be on the UK."

Conservative MPs voted throughout the day in the leadership contest, with a decision expected around 1530 GMT.

A flurry of campaigning in the final hours sparked accusations of dirty tricks.

Nick Boles, a lawmaker who backs justice minister Michael Gove for leader, had to apologise after urging May's supporters to tactically back his candidate to keep out their rival, Andrea Leadsom, a junior energy minister.

In a penitent tweet, Boles said his candidate was not aware of his manoeuvring -- but it will not help Gove's image, after he sensationally withdrew support from leadership frontrunner Boris Johnson to stand himself.

Johnson, the former London mayor and Brexit campaigner who had long been tipped to succeed Cameron, then pulled out of the contest.

May, who has run the Home Office since 2010, is widely viewed as a safe pair of hands. She wanted Britain to stay in the EU but played a minor role in the campaign, and says she is now the best person to unify Britain.

But Leadsom has secured surprisingly strong support following a sound performance in EU referendum debates, and came second in a first ballot of Tory MPs on Tuesday.

In a speech in London to a room packed with supporters, Leadsom said her focus would be on "the continued success of the UK economy".

"Prosperity should be our goal, not austerity," the 53-year-old said.

She dismissed predictions that Brexit could spell economic disaster, and said the fall in the pound to a 31-year low against the dollar was good for exports.

She predicted a return to economic growth when the post-referendum figures are published, adding: "I believe we have a great future ahead of us.

"We need to unite. We need to be positive."

In a round of television interviews, she dismissed reports that she has exaggerated her experience in the financial sector before becoming an MP in 2010.

Former Tory leader Michael Howard acknowledged Leadsom's relative lack of experience, but noted Cameron had no experience in government before becoming prime minister.