Britain's Prime Minister Theresa May speaks during a press conference inside 10 Downing Street in London. Picture: Matt Dunham/AP

London - British Prime Minister Theresa May was fighting for survival on Friday after a draft divorce deal with the European Union provoked the resignations of senior ministers and calls for a vote of no confidence in her leadership.

More than two years after the United Kingdom voted to leave the EU, it is still unclear how, on what terms or even if it will leave the EU as planned on March 29, 2019.

May, who won the top job in the turmoil that followed the 2016 referendum, has sought to negotiate a Brexit deal ensuring the United Kingdom leaves in the smoothest way possible.

But Brexit minister Dominic Raab resigned on Thursday over her deal, sending the pound tumbling. Mutinous lawmakers in her own party openly sought to challenge her leadership and bluntly told her that the Brexit deal would not pass parliament.

May, who has vowed to stay on as prime minister, was asked by a caller on LBC radio to "respectfully stand down". She did not immediately address that part of the caller's question.

British media have been awash with rumours that May would face an imminent vote of no confidence in her leadership from her own Conservative Party lawmakers.

When 48 Conservatives submit letters to the party's so-called 1922 committee, May will face a confidence vote, needing a simple majority of the total votes in order to win.

"For the sake of the Conservative Party and indeed for our country's destiny, I honestly believe that (it) is now time to seek fresh leadership that can carry this country forward outside of the European Union," Brexit-supporting lawmaker Mark Francois wrote in a letter headlined "She Just Doesn't Listen".

However in a boost to May, Michael Gove, 51, the most prominent Brexit-supporting minister in her government, gave his backing to the prime minister, saying he would stay on in government as environment minister.

Asked if he had confidence in May, Gove, who torpedoed former foreign minister Boris Johnson's leadership bid in 2016, told reporters: "I absolutely do."

"I think it's absolutely vital that we focus on getting the right deal in the future, and making sure that in the areas that matter so much to the British people we can get a good outcome."

Other eurosceptic ministers also agreed to stay, according to a tweet from Tim Shipman, Sunday Times political editor.

"RESIGNING WILL NOT HELP"

"Resigning and joining a rebellion is not going to help anything," he quoted an unnamed source as saying.

Sterling, which has see-sawed on Brexit news since the referendum, was flat at $1.2783 on Friday, down almost three cents since a deal was struck on Tuesday.

Brexit will pitch the world's fifth largest economy into the unknown. Many fear it will divide the West as it grapples with both the unconventional U.S. presidency of Donald Trump and growing assertiveness from Russia and China.

Jo Johnson, who resigned as a minister last week, said the situation marked the worst failure of statesmanship since the 1956 Suez canal crisis, when Britain was forced by the United States to withdraw its troops from Egypt.

Amid the turmoil the ultimate outcome remains uncertain.

Scenarios include May's deal ultimately winning approval; May losing her job; Britain leaving the bloc with no agreement; or even another referendum.

To leave the EU on the terms of her deal, May would need to get the backing of about 320 of parliament's 650 lawmakers. The deal is due to be discussed at an EU summit on Nov. 25.

Politicians, officials and diplomats in London openly questioned how long May had left as speculation swirled around London that a leadership challenge could come soon.

By seeking to preserve the closest possible ties with the EU, May has upset her party's many advocates of a clean break, and Northern Ireland's Democratic Unionist Party (DUP), which props up her minority government.

The Daily Telegraph newspaper reported that the DUP had demanded May be replaced as prime minister.

"Oh I haven't had a testy exchange with Arlene," May said. "They've raised some questions with us, they've raised some concerns with us and yes we are looking at those.

"We are still working with the DUP," she said.

NIGHTMARE FOR BUSINESS?

The EU and Britain need an agreement to keep trade flowing between the world's biggest trading bloc and the United Kingdom, home to the biggest international financial centre.

May said she felt the threat of a no deal Brexit personally as she was Type 1 diabetic: "I depend on insulin every day. My insulin is produced by a country elsewhere in the European Union."

May's spokeswoman said there had been strong support from the country's business community for her draft deal but British aero-engine maker Rolls-Royce said it was continuing with its no-deal contingency plans.

The plans include "buffer stocks so that we have all the logistical capacity that we need to carry on running our business," said Chief Executive Warren East.

Proponents of closer relations with the EU in her own party and the Labour opposition say the deal squanders the advantages of membership for little gain.

Supporters of Brexit say that while the divorce might bring some short-term instability, in the longer term it will allow the United Kingdom to thrive. 

Reuters