David Cameron has ruled out a second referendum on Britain's EU membership.

The UK prime minister's spokesperson said holding another vote was “not remotely on the cards”. The clarification comes amid a petition calling for a re-run in the event of a close result and following speculation that the government may go to the country again once the terms of Britain's new relationship have been agreed.

Cameron chaired the first Cabinet meeting since the Brexit vote at midday yesterday, where ministers confirmed plans for a special government unit to draw up options for Britain's renegotiation with the EU.

However, formal negotiations cannot start until Britain activates Article 50 -- initiating the formal two-year procedure for withdrawing from the EU.

Cameron has said this will be a task for the next prime minister, who will not be in place until a Conservative leadership election has concluded by October, writes Independent.co.uk. 

Also yesterday, German Chancellor Angela Merkel said it was understandable that Britain needs time before triggering its exit from the European Union, but warned against dragging out the process.

"We cannot afford to have a long period of uncertainty. I think that would not be good for either the EU's 27 member states or Britain. But I also understand that Britain needs a certain period of time to analyse the situation," she said.

But while Britain considers its options, the leader of Europe's biggest economy also insisted that no back-room deals would be done before the UK triggers Article 50 to leave the bloc, reports AFP.

"There cannot be any informal talks before Britain gives its notice. That to me, is clear," she said.

British finance minister George Osborne said yesterday that his country should only activate Article 50 to leave the EU when it has a "clear view" of how its future in the bloc would look.

Britain's notification will set the clock ticking on a two-year period of negotiations within which a basic withdrawal agreement should be made.

After that "the treaties shall cease to apply to the state in question" -- or in layman's terms, Brexit is a reality.

The talks can in theory be extended if need be -- but only by the unanimous consent of Britain and the other 27 member states.

The head of the Brexit campaign yesterday said it was important to delay the formal process of leaving the EU because people need to "go away on holiday".

Vote Leave chief executive Matthew Elliott welcomed Cameron's decision to delay the "divorce" for several months, despite pressure from Brussels for a rapid departure.

"I don't think we need to rush this process," he told US TV channel CNBC.

"During the campaign there was talk about triggering Article 50 and its process of leaving the EU right away, literally on Friday morning, and I think quite rightly the PM has paused on that which allows the dust to settle, allows people to go away on holiday, have some informal discussions about it, and then think about it come September/October time."

He said Vote Leave had "done lots of detailed planning" for Brexit and suggested Michael Gove was "probably the man to lead the negotiations" - but dismissed the idea of any formal role for Ukip leader Nigel Farage.

Economic turbulence would "settle very quickly", he predicted.

Cameron will face MPs in the House of Commons later this afternoon, and make his first statements on the Brexit vote and its aftermath since he announced his resignation on Friday.

Asked about the possibility of a second vote, the prime minister's spokesperson said: “That's not remotely on the cards. There was a decisive result [in the EU referendum]. The focus of the Cabinet discussion was how we get on and deliver that.”

Earlier, sterling slipped to a new 31-year low against the dollar as George Osborne sought to calm volatile markets.

The pound had dipped to $1.3231 on Thursday night - the lowest since 1985 - as the referendum result came into focus and traders sold sterling. But it recovered slightly over the following 24 hours.

Yet in trading yesterday the pound dipped below that level, as a statement by the Chancellor, George Osborne, highlighting the "strength" of the UK economy, failed to assuage concerns.

Boris Johnson, the figurehead of the Leave campaign and presumed Conservative leadership contender, said in his Daily Telegraph column this morning that "the pound remains higher than it was in 2013 and 2014". But he is believed to have been referring to the pound versus the euro, not the dollar.

In another sign of growing financial stress 10 year government bond yields - known as Gilts - fell below 1 per cent for the first time in history.

Asked during the briefing if Scotland was heading for another independence referendum, Cameron's spokesperson said that was "the last thing [it] needs".

“There was a legal, fair and decisive referendum two years ago,” Cameron's spokesperson said. “The reasons for Scotland being in the UK are as strong now as they were 18 months ago. What we all need to do is to focus on getting the best deal for Scotland and the UK in these negotiations and the last thing Scotland needs now is another divisive referendum.”

The stance will put the government on a collision course with Holyrood and Nicola Sturgeon, who has said a second independence vote is "highly likely" following the UK's decision to Brexit.