WHEN you voice grave concerns over the dire economic consequences of the UK exiting the European Union, people tend to tell you not to worry, that it will never happen.

It would be nice to take heart from such optimistic dismissals of these concerns.

However, such responses have failed to provide any much comfort.

And now we have a poll by Survation, published this week, showing that a majority in the UK, albeit a slim one, would vote to leave the EU if Prime Minister David Cameron’s promised referendum were held tomorrow.

It often feels a lot like we are sleepwalking to disaster on the EU front.

After all, when trying to assess what might happen in the referendum on UK membership of the EU, we must take account of the backdrop of depressingly prevalent xenophobia in Britain right now. Some politicians on the right must shoulder a significant part of the blame for this blight, given their tiresome and ill-informed rhetoric.

The Survation survey showed that, excluding those who were undecided or declared they were unlikely to go to the polling booth, 51 per cent of people in the UK would vote to leave the EU if the referendum, promised by 2017, were held tomorrow. This obviously left 49 per cent declaring they would vote to remain in the EU.

Interestingly, in Scotland, the result was reversed, with 51 per cent in favour of remaining within the EU and 49 per cent expressing a preference to exit.

It is worth observing that it is still a matter of great concern that nearly half of people in Scotland would vote to leave the EU if the referendum were held now. That said, if these poll results were to be mirrored in the actual referendum, we would have a situation of the UK leaving the EU, even though the people of Scotland had voted to remain in the huge free trade block.

This would obviously trigger something of a constitutional crisis. First Minister Nicola Sturgeon could certainly, with great justification, argue that the material change in circumstances she has signalled would be required for a second referendum on Scottish independence had occurred.

And in such a scenario, regardless of your viewpoint on independence, you can well imagine that much of the business community in Scotland would not welcome further uncertainty at a time when they were having to deal with the disaster of an exit from the EU. Then again, the attitude of some businesspeople might depend on their assessment of the chances of an independent Scotland being able to remain, or get back into, the EU.

A poll published this week by TNS showed that, excluding those who said they did not know, 53 per cent of people would vote for independence if another referendum were held tomorrow.

Putting the Scottish constitutional issue aside, it is difficult to overstate how alarmed we should be about the possibility of the UK exiting the EU.

You get the impression from speaking to businesspeople in Scotland that the vast majority is in favour of remaining within the EU. You keep hearing that the EU is not perfect. Maybe not. However, with the notable exception of its unsupportive attitude towards Greece, the EU is pretty good in most other respects.The huge advantages of being part of the EU certainly dwarf the downsides.

Forecasts of very steep and fast falls in UK gross domestic product in the event of an exit from the EU seem to be right on the money. You cannot imagine there would be anything other than huge negative consequences from exiting the huge single market that is the EU.

And what about all those global trade treaties that the EU has negotiated with countries around the world. A recent visit to Taiwan highlighted the importance of free trade agreements. The newspapers were dominated by headlines about the government’s efforts to secure crucial trade deals with other countries, and the importance of these to the Taiwanese economy.

And then there are the vital checks and balances that the EU provides in crucial areas such as human rights. This safety net is even more important in these grim days of UK austerity.

We underestimate at our peril the chances of a vote to exit the EU.

There was another slightly alarming poll on this front this week, showing 57 per cent of the British public did not believe the UK should increase the number of refugees it takes from countries such as Syria or Libya. And Mr Cameron has found himself in conflict with other EU member states over the UK’s relatively reluctant attitude to pitching in and helping out with the refugee crisis.

There is a lot of fretting in financial markets about the slowdown of growth in China and this is undoubtedly an issue given the weakness of other major world economic powers, including the UK with its dangerously unbalanced and unconvincing recovery.

But we should remember, from bitter past experience including that in the run-up to the global crisis, that financial markets are famously short-sighted.

What we should actually be worrying about most is the risk of exiting the EU, and no longer having the single market and access to other crucial free trade agreements.

Mr Cameron will presumably try to bring us back from the brink of an exit once he is happy that his macho posturing has addressed whatever he perceives to be the problems of the EU.

Notwithstanding this, against a backdrop of lamentable xenophobia and jingoism, the risk of the electorate voting to leave the UK in Mr Cameron’s politically motivated and entirely unnecessary referendum is crystal clear.

And the economic consequences of an EU exit would seem likely to be beyond the imagining of those who are geared up to vote to leave.