J EREMY CORBYN may have it in for tax havens, but they are not all cursing the Labour leader. Well-heeled types worried about the prospect of a Corbyn-led government have been buying property on Guernsey with a view to moving to the island, attracted by its flat 20% income-tax rate and lack of capital-gains or inheritance taxes. Demand for homes there is buoyant, and Jo Stoddart of Locate Guernsey, an investment-promotion agency, says queasiness over Mr Corbyn is one of the main reasons.

The opposition leader makes no secret of his disdain for the rich. The real divide in Britain, he said recently, is not over Brexit but “between the many, who do the work, create the wealth and pay their taxes, and the few, who set the rules, reap the rewards and dodge their taxes.” The super-rich, he has warned, are “on borrowed time”.

Small wonder, then, that plutocrats are seeking advisers’ counsel—and increasingly taking action—to keep their incomes, mansions and pensions out of Labour’s clutches. “How to Corbyn-proof your wealth”, an event held in London in February by an investors’ club, sold out.

Bookmakers offer odds as short as 3/1 on Mr Corbyn becoming the next prime minister. If that happened, says the chief executive of a FTSE 100 company, the rich would “take all the money offshore, wait for the economy to crash, and come back and get richer.” Private-client advisers have warned of Britain’s multi-millionaires moving up to £1trn ($1.3trn) out of the country. But the “mass affluent”, those with liquid assets in the hundreds of thousands, also have cause to fret.

Such fears have fluctuated in line with recent political turmoil. Wealth advisers agree that clients worry more about Mr Corbyn than Brexit—though the two are linked, as some fear a disorderly Brexit precisely because it could usher in a Labour government. Iain Tait of London & Capital, who advises dozens of rich families, says anxiety about Labour has reached its highest point yet in the past couple of months. When clients of Saunderson House, a wealth manager, were asked in October about the biggest threat to their finances, the most likely answer, mentioned by 42%, was a change of government. The number would almost certainly be higher now.

The worries fall into three categories. The first concerns existing tax and pension arrangements. Labour is likely to target pension tax relief for high earners. On income tax, it has promised to reintroduce the 50% rate on earnings over £123,000 (rather than £150,000) and add a 45% rate that kicks in at £80,000. It is likely to reverse the Tories’ cuts to capital-gains tax. And it is expected to tighten the inheritance-tax regime, possibly by reducing or removing allowances for those giving to discretionary trusts or handing property or gifts to relatives. To cap it all, Labour promises to levy VAT on private-school fees.

The second area is brand new taxes. Labour hopes to raise almost £5bn a year from a new financial-transactions levy. This would cream 0.2% off every transaction executed by financial firms. Some hedge funds are reportedly considering moving overseas in response. The bigger worry is the possibility of a wealth tax on assets, perhaps focused on high-value homes, to help fund social care. In 2012 John McDonnell, who has since become shadow chancellor, backed a proposal for a one-off, 20% wealth tax to help reduce government debt.

The third category—and the biggest bogeyman—is the spectre of capital controls, measures to restrict the flow of capital in and out of the country, in the event of severe economic turbulence. Labour has repeatedly denied it would consider such a measure, last seen in Britain in the late 1970s. Even Mr Corbyn’s critics see it as a long shot. Nevertheless, contingency plans are being put in place. A year ago, says Mr Tait, it would have seemed “ludicrous” to be mulling measures to protect against capital controls. Yet clients raised the issue in “around half” the meetings he attended in the run-up to Easter. As an insurance policy, some have arranged for custody of their investment accounts (used to buy and sell securities) to be moved to the Channel Islands or Switzerland. Changing the jurisdiction in which accounts are booked is all about “asset access”, not tax, says Mr Tait.

With a property-based wealth tax in mind, some rich folk are accelerating the transfer of homes to children. “They might have done this anyway when the kids were in their 20s. Now they’re doing it in their teens,” says one adviser, who has “dozens” of clients who have opted to speed up handovers. Some are also using up tax-free pension allowances, or vesting tax-free cash, earlier than required, for fear of such benefits evaporating under Labour.

Sunny places for gloomy people

A smaller number are considering moving offshore. Rather than emigrating now, most of these Jeremiahs are considering buying foreign residence permits to hold alongside their British passports, in order to be well placed to hop abroad if things turn nasty. Advisers say they are looking not only at obvious places like Monaco and the Channel Islands but also at EU countries that have become friendlier to rich foreigners, such as Portugal (where a “golden visa” can be bought for €500,000, or $561,000) and Italy (where income from abroad can be taxed at a flat €100,000).

Among those tempted to up sticks are resident “non-doms”: foreigners who live in Britain but declare their domicile as elsewhere to avoid tax on their non-British income. The Tories took away some of their privileges in 2016, but the non-doms are still handled fairly generously for up to 15 years. The threat of a Corbyn government, though, is leading some who were wavering to go elsewhere. Another wealth adviser has Swedish and French clients who are returning home. “Sweden and France, those well-known tax havens!” he guffaws.

Were Britain’s 90,000 or so non-doms to leave, many Corbynistas might say good riddance. Some Labour strategists believe the public would welcome a falling-out with the super-rich. Mr Corbyn has long accused them of dodging tax and contributing little to the economy. But non-doms paid a not-so-paltry £9.4bn in tax—equivalent to a third of the transport budget—in the year to April 2016.

Mr McDonnell’s team dismisses the bleating from Belgravia as alarmist. Fears over a wealth tax are as misplaced as those concerning capital controls, aides say. Yes, income tax will rise, but to nowhere near the rates of the 1970s. Mr McDonnell may have an avowedly Marxist past, but he has been on a charm offensive in the City, assuring moneymen he has nothing up the sleeves of his branch-manager suit.

Moreover, when it comes to squeezing the rich there is less to separate the two main parties than the Tories admit. As well as turning the screws on non-doms, the Conservatives have cut high-earners’ tax-free pension allowances and are mulling an inheritance-tax grab. The chancellor, Philip Hammond, has warned that taxes must rise to fund an ageing population.

Still, tone matters, and there is a difference between measured tax increases and what looks to some like anti-capitalist bloodlust. Mr Corbyn has said he is “coming for” the rich. Some of Labour’s plans suggest a taste for confiscation. The party wants to nationalise several industries, including water, for which it is considering basing compensation for investors on “book” value—currently a third of the industry’s market value—or even less. A plan to snatch 10% of shares in big British firms and give them to workers and the state has nauseated many business leaders. “The rich are prepared for higher taxes,” says Bobby Vedral of Macro Eagle, an advisory business, “but not for expropriation.”

Mr Vedral caused a ruckus in 2017 when he predicted a Britain led by Mr Corbyn would be like “Cuba without the sun”. That is unfair—but ever more of the monied seem unwilling to take any chances.