Theresa May has told world leaders and corporate chiefs that Britain remains "open for business" despite its decision to leave the European Union.

In a speech to the World Economic Forum in Davos, Switzerland, the Prime Minister insisted that Brexit did not mean the UK turning its back on the world but seeking out new trading partners and allies around the globe while maintaining its friendship with European neighbours.

Voters who opted for Brexit in last year's referendum were choosing to "leave the EU and embrace the world", and Britain would as a result become "even more globalised and internationalist in action and in spirit", she said.

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Mrs May was speaking as a series of major businesses made clear they were reconsidering their plans for operations in the UK in the wake of her announcement on Tuesday that she will take the country out of the European single market.

HSBC indicated 1,000 jobs from the bank's London business are on course to move to Paris while Barclays is looking to route activities through Ireland and Germany and Switzerland's UBS is preparing to move posts from the UK to the continent.

Car giant Toyota's chairman Takeshi Uchiyamada told the Financial Times: "We have seen the direction of the Prime Minister of the UK, (so) we are now going to consider, together with the suppliers, how our company can survive."

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Writing in The Sun, Mrs May urged people to "stop fighting the battles of the past" and accept the UK is going to leave the European Union, insisting Brexit could make the UK stronger and fairer.

Mrs May said the modern industrial strategy she will launch next week was part of a plan to turn post-Brexit Britain into a "great meritocracy" and create a "more united nation" that "works for ordinary people".

But the European Parliament's chief Brexit negotiator Guy Verhofstadt warned it was an "illusion" to suggest the UK could leave the EU but retain the benefits of tariff-free trade.

Writing in the Guardian, Mr Verhofstadt said no one in the EU wanted to "punish" the UK.

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But he said "it is an illusion to suggest that the UK will be permitted to leave the EU but then be free to opt back into the best parts of the European project, for instance by asking for zero tariffs from the single market without accepting the obligations that come with it".

Mrs May told the WEF that a post-Brexit Britain will "step up to a new leadership role as the strongest and most forceful advocate for business, free markets and free trade anywhere in the world".

She acknowledged that the country was facing a "period of momentous change".

"It means we must go through a tough negotiation and forge a new role for ourselves in the world," she said. "It means accepting that the road ahead will be uncertain at times, but believing that it leads towards a brighter future for our country's children, and grandchildren too."

But she insisted that the UK would "emerge from this period of change as a truly Global Britain - the best friend and neighbour to our European partners, but a country that reaches beyond the borders of Europe too; a country that gets out into the world to build relationships with old friends and new allies alike."

Already, she said, Australia, New Zealand and India had started discussions on future trade ties with the UK, while China, Brazil and the Gulf states had expressed an interest in striking trade deals.

She said post-Brexit Britain would remain a "hub for foreign investment", a "home to people from around the world" and a supporter of multi-lateral organisations like the United Nations, Nato, the International Monetary Fund and the World Bank.

"We are going to be a confident country that is in control of its own destiny once again," said the Prime Minister. "And it is because of that that we will be in a position to act in this global role.

"Because a country in control of its destiny is more, not less, able to play a full role in underpinning and strengthening the multilateral rules-based system."

In an attempt to reassure the remaining 27 EU members of the UK's continuing goodwill, Mrs May said: "Our decision to leave the European Union was no rejection of our friends in Europe, with whom we share common interests and values and so much else.

"It was no attempt to become more distant from them, or to cease the co-operation that has helped to keep our continent secure and strong.

"And nor was it an attempt to undermine the European Union itself. It remains overwhelmingly and compellingly in Britain's national interest that the EU as an organisation should succeed.

"It was simply a vote to restore, as we see it, our parliamentary democracy and national self-determination. A vote to take control and make decisions for ourselves.

"And, crucially, to become even more global and internationalist in action and in spirit too."

Responding to reports of the Toyota boss's comments, a Downing Street spokesman said: "The automotive industry and finance are key areas for us and we will be, as we go into the negotiating period, looking at how we can ensure the best possible access to the European market for our key sectors."

Asked whether Toyota might receive a "letter of comfort" of the kind provided to Nissan to reassure it about future trading conditions in the UK, the Number 10 spokesman said: "There was no deal offered to Nissan. We have had discussions with the automotive industry - not just Nissan and Toyota, but across the sector. We have listened to their concerns and what they want to see going forward."

Mrs May said that things would be "different" after Brexit when she was asked to respond to statements from some European leaders that Britain will be poorer after withdrawal from the EU.

The PM told the BBC that she believed a good trade deal would be in the best interests of both the UK and the EU, before adding: "It will be different, we won't be members of the European Union any longer. We will be outside the European Union, but I want to build a strong, strategic partnership with the EU."

Mrs May side-stepped answering whether she was disappointed that major banks were planning to move some jobs out of the UK, but said she had been stressing the "positive" aspects of doing business in the City of London during meetings with major financial organisations.

The PM said: "I have had a very good, positive discussion with banks about the benefits of the City of London, about what it is that has brought them to the City of London and how we can continue to build on that for the future, and there are huge benefits for investment in the UK."