Brexit: Boris Johnson launches pitch to be the Prime Minister that leads Britain out of Europe

Former Mayor of London says 'no need for haste' in initiating Article 50 and beginning process of negotiating Britain’s exit from the EU

Boris Johnson insisted that the result of the referendum did not represent a retreat into isolationism and that Britain would remain a "great European power"

Boris Johnson has launched his pitch to be the Prime Minister that leads Britain out of Europe, brushing aside fears of political upheaval and economic turmoil and promising he could deliver “a more secure and prosperous future” outside the EU.

Filling the political vacuum left by David Cameron’s announcement that he would resign and make way for "fresh leadership" to negotiate Britain’s exit from the European Union, Mr Johnson sought to reassure voters and the markets.

He said was there was "no need for haste" in beginning the process of negotiating Britain’s exit from the EU and insisted that the result of the referendum did not represent a retreat into isolationism and that Britain would remain a "great European power".

"We cannot turn our backs on Europe. We are part of Europe,” he said.

But the former London mayor, who is considered the clear favourite to succeed Mr Cameron when he steps down in the autumn, will face unprecedented challenges after unleashing the biggest political upheaval in recent British history.

In an uncompromising joint statement the President of the European Council Donald Tusk and head of the Commission Jean Claude Junker said they expected the Brexit negotiations to be a "painful process".

They added that Britain should not expect special treatment, warning that any agreement to be "concluded with the United Kingdom as a third country, will have to be balanced in terms of rights and obligations".

Handelsblatt, a German business newspaper, said it had obtained a copy of an emergency plan entitled "German strategy for Brexit" that warned against treating the UK too leniently for fear of encouraging other countries to follow suit.

It said there would be "no automatic access to the single market" in order to "avoid offering false incentives for other member states when establishing new arrangements".

Financial markets recovered some of the ground they lost after the initial panic of the result which at one stage saw the pound fall to its lowest level against the dollar since it was freely traded.

But by the close of the markets Friday, sterling was still trading at levels not seen since the financial crash and the FTSE index of the 250 leading shares was down nearly seven per cent on the day.

Meanwhile in Scotland, which voted to remain in the EU, the First Minister Nicola Sturgeon said a second independence referendum was "highly likely".

Nicola Sturgeon said it was "democratically unacceptable" that Scotland faced the prospect of being taken out of the EU against its will.

She said the Scottish government would begin preparing legislation to enable another independence vote.

Scotland voted in favour of the UK staying in the EU by 62 per cent to 38 per cent while the UK as a whole voted to leave by a margin of 52 per cent to 48 per cent.

Just over an hour after the result was officially declared David Cameron appeared outside Downing Street to announce he had told the Queen of his intention to resign.

Flanked by his wife and at one stage appearing close to tears Mr Cameron said it would be wrong for him "to be the captain that steers our country to its next destination".

He announced that he would stay on in a caretaker capacity but expected a new leader to be in place by the time of the Conservative Party conference.

His decision fires the starting gun on a Tory Party leadership contest with Mr Johnson the clear favourite to take over. He will certainly face a challenge from, among others, the Home Secretary Theresa May and possibly the new Work and Pensions Secretary Stephen Crabb. George Osborne’s hopes of succeeding his friend in Downing Street now seem implausibly small.

In his statement Mr Cameron went back on his pledge during the referendum campaign to carry on regardless of the result.

"We must now prepare for a negotiation with the European Union. Above all this will require strong, determined and committed leadership," he said.

"I think the country requires fresh leadership to take it in this direction.

"I will do everything I can as Prime Minister to steady the ship over the coming weeks and months but I do not think it would be right for me to try to be the captain that steers our country to its next destination."

In a statement to civil servants who will have to support the new Prime Minister with Brexit negotiations the Cabinet Secretary Sir Jeremy Heywood said it fell to them to "carry forward the clear decision of the British people to leave the European Union".

"I am confident that we will do this with our customary calm, integrity and commitment," he said.

The political turmoil was not limited to the Government and the Conservative Party.

Jeremy Corbyn will next week face a no confidence motion tabled by two senior Labour back benchers after accusations that he led a lack lustre campaign that failed to mobilise Labour supporters.

The motion will be discussed at a meeting of the Parliamentary Labour Party on Monday and could lead to a secret ballot of MPs on Mr Corbyn’s future.

"I believe that, unless we change our leader, we are not going to win the next election," Ann Coffey one of the two signatories on the motion said.

"And as we are going to not be part of the European Community, we need more than ever a Labour government that will protect the interests of working people, and that has to be our paramount consideration rather than our loyalty to any particular leader."

A spokesman for Mr Corbyn condemned the motion as a "self-indulgent act", although he acknowledged it had been discussed at a post-referendum meeting of the shadow cabinet.

"It is a time when our party should be uniting to deal with the real issues that face Britain and the real issues that face the people of Britain, and so to create divisions in the party is a bit of a self-indulgent act," the spokesman said.

Former Labour cabinet minister and EU commissioner Lord Mandelson also said the referendum campaign showed Mr Corbyn "can't cut it" as leader.

Mr Corbyn had been due to speak at Leftfield at Glastonbury on Sunday, but his spokesman said he had pulled out.

The Ukip leader Nigel Farage described the Brexit victory as "dawn was breaking on an independent United Kingdom". Provocatively he said he hoped the vote would be a catalyst for the complete collapse of the European Union.

But the former Prime Minister Tony Blair said the referendum result has made him "sad for our country, for Europe, [and] for the world".

US President Barack Obama insisted that the "special relationship" between the UK and Washington would endure following the referendum result. Mr Obama said both the UK and European Union would remain "indispensable partners".