Tom Welsh:

Whenever the Conservatives look likely to win an election, some celebrity has a tantrum and threatens to leave for Europe. They rarely do. Their histrionics are a performance, designed to show they are “nice” unlike those nasty Tories. When they come back down to earth, they realise that there are few better places to live than Britain, that much of Europe is less liberal and more provincial, and that they are not, in fact, willing to uproot their families and upend their careers for the sake of making a bad point.

If Labour forms a government this week, it is another matter entirely. For millions of people, leaving the country will be the most rational thing they can do. And the crushing burden of tax the party will need to impose to pay for its lunatic agenda, not merely on higher earners but on business owners and those who rely on income from capital, is not even the most important reason.

Yes, many people will suddenly find that Britain is not a tax-efficient place to live (and one of the elephants in the room in this campaign is that, even now, we are not a low-tax economy and have been standing still as our competitors have boosted their competitiveness).

But the most noxious effect of Labour’s agenda will be to demolish hope and ambition.

There will be no point working for a better life because, if you succeed, the government will want to steal it away from you and your children, redistributed, yes, to the needy but also to those who have not bothered to work so hard.

Ideologically, your efforts will be reinterpreted, too. The subtext of Jeremy Corbyn’s tirades against billionaires is that any and all wealth has been unfairly accumulated. If you set up a company, employ workers and expand, you will be viewed not as socially useful but, at best, as a cash cow and, at worst, evidence of a broken system in which no individual should have more than any other.

If you are young and ambitious, why would you choose to yoke yourself to such a system? Why devote your life to working on behalf of others, and then be damned for doing so? That’s if you are even allowed to take a different path to everyone else in Labour’s “workers’ democracy”. From schools and trains to energy, the party is no great fan of choice.

Of course, for most of us, we will have little option but to stay. Family ties, property and love of country will be enough to keep us here, and if the consequence of Corbyn’s policies is capital controls to stem a flight of money, leaving will be that bit harder.

But Britain already has one of the largest expat populations per capita in the world: we are an open society where people have always looked overseas to make their fortunes. For many people, the question will just be: where? Australia, New Zealand, Singapore, the low-tax economies of Eastern Europe, Portugal, America, Canada: where will you go?

If you are young and ambitious, why would you choose to yoke yourself to such a system? Why devote your life to working on behalf of others, and then be damned for doing so?