A single question was on the lips of the thousands of investors gathered in the city of Liverpool in northwest England this week: what will happen if Britain leaves the EU?
From a small English milk producer to a large Indian employer, no fewer than 30,000 businessmen and women gathered for the International Festival for Business, the largest meeting of its kind in Britain.
The UK will go to the polls on June 23 to settle the debate on its continued EU membership.
The campaigns for and against were this week thrown into disarray after the killing of lawmaker Jo Cox just seven days before the vote.
Polls have indicated growing support for leaving, days ahead of the referendum with markets reacting nervously.
"The European referendum is clearly bringing a degree of uncertainty to business markets," said Ian McCarthy, director of the International Festival for Business.
"Let's hope that when there is a decisive result toward the end of June, business can get back to what it does best which is developing products and services," he said.
The vast exhibition hall on the banks of the River Mersey was buzzing with product presentations, conferences and private meetings, where organisers expect contracts worth £265 million ($374 million, 334 million euros) to be inked.
But in every spare moment, talk turned to the potential fallout of an exit: whether Prime Minister David Cameron's gamble in calling the vote could imperil his political future; and whether a break with Brussels bureaucracy could be positive.
"In case of a Brexit we would have the biggest recession in a generation, but we would survive," said Will Butler-Adams, CEO of Brompton Bicycle, the maker of iconic folding bikes.
"For my business I prefer to be in Europe but we would survive anyway, we would adapt."
Anyone making predictions about what would happen however, is wasting time, he added.
"You can't make figures in advance about the consequences because a Brexit would not happen overnight."
International organisations, including the International Monetary Fund, have warned that Britain's economy will suffer if it leaves.
- 'Alone and isolated' -
Proudly showing off his antique sewing machine, master leather craftsman Keith Hanshaw said he was not afraid.
From his studio in Huyton, in the suburbs of Liverpool, his small company The Leather Satchel exports bags as far as Japan and Australia.
"In the short term, nothing good would come from a Brexit. But on a medium to long term, it could help to sign free-trade agreements," said Hanshaw, an affable company executive director with a neatly trimmed beard.
Leaving the bloc would allow Britain to negotiate trade deals without having to take into account the diverse interests of the EU's 27 other members, he believes.
Hanshaw is planning to vote in favour of Brexit, but admits that many of his employees are happy with the status quo.
The economic redevelopment of Liverpool and much of post-industrial Britain is vulnerable to shocks.
From the opening of the port city's first docks in 1715 to 1960 the city enjoyed two and a half centuries of prosperity.
It was the starting point of goods destined for export around the British Empire, and a departure point for emigrants from Ireland and around Europe seeking a better life in the United States.
The city experienced a steep decline after 1960, but has experienced a burgeoning revival in the last two decades.
Its docks, once the foundation of the city's wealth that fell into obsolescence, have been regenerated as a cultural and tourist hub thanks to a share of the £1.5 billion in European funds that the city has received, according to local authorities.
Work is underway to develop a new port, capable of accommodating the latest generation of container ships, due to open this year.
"The Brexiters who demand that we should leave Europe quite simply tell you that the grass is greener on the other side," said Joe Anderson, mayor of Liverpool and a member of the centre-left Labour party.
"My belief is that there would be desert on the other side and a lonely path for the UK left alone and isolated."