Angry members of the European Parliament (MEPs) have pressed Britain to end the uncertainty that has gripped markets worldwide after last week's referendum, saying that if it intends to leave the bloc it should start the process immediately.

The MEPs called on the UK government to respect its people's democratic decision and start the withdrawal procedure as soon as possible by activating Article 50 of the Treaty on European Union.

In an unprecedented emergency session on Tuesday, called after Britain voted to leave the union, European Union Commission President Jean-Claude Juncker demanded that Britain clarify its future.

"I want the UK to clarify its position. Not today, not tomorrow at 9am, but soon," he told MEPs in Brussels.

"We cannot allow ourselves to remain in a prolonged period of uncertainty."

Juncker said that he had banned his policy commissioners from holding any secret talks with Britain on its future until London triggered the EU constitution's Article 50, which sets in motion a two-year process to split. 

"No notification. No negotiation," Juncker said to resounding applause.

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Nigel Farage, a British MEP and a leader in the "Leave" movement, was booed and jeered when he urged Europe to give Britain a good trade deal when the so-called Brexit takes place, saying jobs in Germany's car sector might be at stake otherwise.

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"Why don't we just be pragmatic, sensible, grown-up, reasonable ... and cut a sensible tariff-free deal?" he asked.

In a speech interrupted several times due to the noise, Farage warned: "The UK will not be the last member state to leave the European Union."

When Juncker mentioned the Brexit vote in a speech, Farage cheered, to which the EU Commission president joked, and quipped: "The British people voted in favour of the exit - why are you here?"

But bearing out his words, French far-right leader Marine Le Pen called the British vote "an extraordinary victory for democracy - a slap for a European system based more and more on fear, blackmail and lies".

UK Prime Minister David Cameron, meeting EU leaders on Tuesday for the first time since the referendum, vowed that the UK will not turn its back on Europe despite the vote.

"These countries are our neighbours, our friends, our allies, our partners, and I very much hope we’ll seek the closest possible relationship in terms of trade and cooperation and security, because that is good for us and that is good for them," Cameron said as he entered the EU summit building. 

Way forward

German Chancellor Angela Merkel said she will use "all her strength" to prevent the EU from drifting apart. She and other EU leaders were beginning a two-day summit later on Tuesday to hear Cameron's position and chart the way forward.

Britain's "Leave" leaders hope that the nation can still enjoy many perks of the EU internal market for business, while being able to deny EU citizens entry to Britain to address concerns about immigration that were a key factor in the vote.

But Merkel, head of the EU's biggest economy, made clear that this is not an option.

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In an address to the German parliament before heading to Brussels, Merkel said she expected that Britain would want to maintain "close relations" with the EU once it left - but warned it could not expect a business-as-usual approach.

"Whoever wants to leave this family cannot expect to have no more obligations but to keep privileges," she said.

"We will ensure that the negotiations are not carried out with the principle of cherry picking," she said.

Merkel and other leaders joined Juncker in saying there could be no talks with Britain until it started the formal procedure to leave.

MEPs paid tribute to Britain's commissioner in Brussels, Jonathan Hill, who resigned after last week's vote.

He wept in the parliament on Tuesday as he received a standing ovation.

Source: Al Jazeera and agencies