The departure of brash former commodities trader Nigel Farage would sideline one of the most outspoken and effective anti-EU campaigners from the debate about how to sever Britain's ties with the other 27 countries in the bloc. Britain has no firm plan for how it wants to proceed in negotiations with the EU over a future relationship. European leaders say London must choose between continuing to allow free movement of EU citizens, or expulsion from the common market.
But it could also give his UKIP party-which won just a single seat in parliament last year despite placing a strong third-an opportunity to select a less-polarising figure and take on the mainstream in what is likely to be a radically altered political environment.
Both of Britain's two main political parties are in disarray following the vote to leave the EU, with the ruling Conservatives seeking a replacement for Prime Minister David Cameron and lawmakers from the main opposition Labour Party voting to withdraw confidence leader Jeremy Corbyn.
"I have never been, and I have never wanted to be, a career politician. My aim in being in politics was to get Britain out of the European Union," Farage told reporters.
"During the referendum campaign, I said 'I want my country back'. What I'm saying today, is, 'I want my life back,' and it begins right now."
The acrimonious leadership battles in the main political parties have added to uncertainty at a time when Britain is embarking on its biggest constitutional change since the dissolution of its empire in the decades after World War Two.
The government, which failed to convince voters that a Leave vote would cause economic harm, is now racing to reduce the damage.
George Osborne, the finance minister, has abandoned his target of balancing the budget within four years and floated the idea on Sunday of a quick cut in corporate tax to 15 percent from 20 percent. The opposition Labour Party accused him of trying to turn Britain into an offshore tax haven.
The Leave vote has the potential to bring UKIP, an upstart party formed to campaign over the single issue of exiting the EU, into the main stream, a difficult hurdle in Britain which has no proportional representation.
UKIP candidates placed second in scores of constituencies in the last general election, challenging the Conservatives across much of southern England and contributing to an erosion of support for Labour in working class areas in the north.
This week will see the Conservatives start the process of whittling down the candidates to succeed Cameron, who has said he will leave it to his successor to withdraw from the EU.
Theresa May, a party stalwart who has run the law-and-order portfolio in the cabinet for six years, is the favourite to succeed Cameron despite having campaigned to remain in the EU. She is opposed by four other candidates, including Justice Secretary Michael Gove, a Leave campaigner who caused high political drama last week by turning against his ally, former London mayor Boris Johnson, driving him from the race.
Despite the June 23 vote for 'Brexit' with 52 percent support, Britain has not yet invoked Article 50 of the EU's Lisbon Treaty to begin the formal process of breaking away.
While all of the Conservative candidates to succeed Cameron say there is no going back on the decision to leave, some anti-Brexit politicians say it is still not a foregone conclusion.
Law firm Mishcon de Reya said on Monday it had started legal action to demand the British government win legislative approval from Parliament before triggering the divorce process. Most of the 650 members of the House of Commons opposed Brexit before the vote.
"The outcome of the Referendum itself is not legally binding and for the current or future Prime Minister to invoke Article 50 without the approval of Parliament is unlawful," Kasra Nouroozi, a partner at Mishcon de Reya, said in the statement.
It has been in correspondence with government lawyers since June 27 to seek assurances for its clients that the government will respect the sovereignty of British parliament.On financial markets, the pound rose 0.2 percent against the dollar on Monday, while the FTSE 100 index of leading shares was flat.
The departure of brash former commodities trader Nigel Farage would sideline one of the most outspoken and effective anti-EU campaigners from the debate about how to sever Britain's ties with the other 27 countries in the bloc.
Britain has no firm plan for how it wants to proceed in negotiations with the EU over a future relationship. European leaders say London must choose between continuing to allow free movement of EU citizens, or expulsion from the common market.