DAVOS, Switzerland Prime Minister David Cameron called on business on Thursday to speak out in favour of Britain staying in a reformed European Union, but warned those wanting a quick fix that he would settle only for the "right deal".
Cameron, who was attending the World Economic Forum in the Swiss resort of Davos, hit back at criticism that his decision to call a referendum increased global uncertainty, saying he was a democrat who wanted to "confront this issue" once and for all.
His appeal, though, was to a largely sympathetic, if small, audience, increasingly worried that a Brexit, or British exit, would further hurt their businesses and London's status as a financial centre at a time when the global economy is shaky.
"I hope that business ... and other organisations won't hold back. I would say don't hold back right now, even though the question isn't settled," Cameron said, adding he hoped to achieve agreement with the European Union at a February summit.
"If there's a good deal on the table I will take it and that's what will happen. But I do want to be very clear, if there isn't the right deal, I'm not in a hurry," he told a half-empty hall at the leading business conference.
The referendum will not only shape Britain's role in world trade and affairs, but also the EU, which is struggling to maintain unity over migration and financial crises.
Cameron described the referendum, which could be held as early as June if he wins a deal next month, as "a massively important generational question for Britain and for Europe".
The prime minister met business leaders in Davos after being boosted by pledges from several banks to fund a campaign to keep Britain inside the European Union and by senior European leaders who said a Brexit would be a "tragedy" and "disaster".
"We would all be worse off if you were to leave," Dutch Prime Minister Mark Rutte, whose country holds the EU presidency for the first half of this year, told a British questioner.
Paul Polman, the head of consumer goods company Unilever, likened a possible Brexit to a messy, costly and ultimately regrettable divorce.
"I think the UK has to ask themselves some profound questions, even the people that emotionally would say right now I need a short term solution that I might run away from something," he told Reuters.
"It’s not necessarily the right long-term solution."
But the British leader must still persuade Britons, who according to opinion polls are deeply split over EU membership.
Although official campaigning on both sides of the debate will not begin until Cameron has finished negotiations with the bloc which he hopes will secure a better membership deal for Britain, the battle lines have already been drawn.
And Cameron's courting of companies and pledges from banks to help fund those lobbying to stay in the EU were swiftly met by the 'out' campaign saying the donations were proof that the EU protects vested interests.
Many British businessmen say the EU needs deeper reform to secure them the financial advantages they need. They want the single market in the digital and service industries to be developed and bureaucracy to be cut.
"If Britain decides to stay in a reformed Europe at no stage will you hear me say that 'that is perfection, this organisation is now fixed'," Cameron told the audience.
"There are many things that are imperfect about the European Union today and there'll be many things that will be imperfect about the European Union even after this negotiation."
(additional reporting by Paul Taylor in Davos and Kylie MacLellan in London, editing by Anna Willard)