Britain\'s EU divorce likely to be acrimonious
BRUSSELS - Britain's leaving the European Union promises to be a fraught divorce, with the first exchanges showing how breaking up will be hard to do after more than 40 years together.
With European Commission chief Jean-Claude Juncker warning that Brexit would "not be amicable", here are the next steps in the complicated process that Brussels and London will have to navigate.
The process is proving acrimonious before it has even started.
The European Union wants to move on quickly so as to limit the fallout from the Brexit vote as fears grow that other member states such as Denmark and the Netherlands might seek a referendum of their own.
Britain should accordingly start negotiations to quit the bloc "as soon as possible, however painful that process may be," EU president Donald Tusk said after an emergency meeting with his peers.
British Prime Minister David Cameron, announcing his resignation, insisted however that it would and should be up to his successor to begin the process, most likely in October.
European Commission chief Jean-Claude Juncker said he could not understand the delay.
"I do not understand why the British government needs until October to decide whether to send the divorce letter to Brussels," Juncker told German public broadcaster ARD.
"It is not an amicable divorce but it was also not an intimate love affair," he added.
Some British commentators say the talks could be delayed even longer, possibly until after French presidential elections in 2017, as a new 'Brexiteers' government holds back in hope of getting a better deal.
To begin the withdrawal process, Britain must invoke Article 50 of the Lisbon treaty, which has never been used before.
Article 50 says that "any member state may decide to withdraw from the Union in accordance with its own constitutional requirements" and sets out the procedures to do so.
The first step is to inform the European Council of member states, led by Tusk, which sets the clock ticking on a two-year timetable of negotiations.
The talks can be extended by mutual agreement, if need be, to allow the hugely complex process of unpicking the reams of legislation joining Britain and the EU.
Tusk has warned that getting approval for a deal from each of the remaining 27 member states, plus the European Parliament, could take a further five years -- making seven years in all.
The British government said in a report in February that it could take up to 10 years to tie up all the loose ends.
Article 50 also states that a former EU nation can seek to rejoin the bloc, under Article 49, which begins the membership process from zero.
The simplest and most frequently cited option for a settlment is for Britain to join Iceland and Norway as members of the European Economic Area, which would give them access to the EU single market.
That however would mean London still having to obey the EU's rules despite no longer having any say in how they are decided, plus still having to pay money to Brussels.
The similar Swiss model is another possibility but Switzerland has fallen foul of the EU over limits it has imposed on the free movement commitments it made to secure access to the EU market.
Other options include a free trade deal with the EU or a customs union similar to that between Turkey and the EU. Failing that, it would simply become a trading partner like the United States or China.
London would have to negotiate the status of the two million Britons living or working in the EU.
This would particularly affect their pensions and rights to healthcare, with the British government noting: "UK citizens resident abroad, among them those who have retired to Spain, would not be able to assume that these rights will be guaranteed."