Currently, those on the rich list can opt to pay a lump sum to the local tax service, with their spending, rather than income, being used to gauge their wealth.

The new rules are set to expand what is considered taxable for the super-rich, and will apply in 2016 to anyone who moves to the country as of 2014.

Rich foreigners who already live in Switzerland will be allowed a grace period, up to 2020, before the new rules apply.

Around 5,000 people benefit from the current system, but it has raised hackles in Switzerland because it is only open to foreigners.

Last year, opponents of the existing rules launched a petition to demand that they be abolished outright.

Under Switzerland's renowned system of direct democracy, opponents managed to open the way for a referendum within the next two to three years.

A handful of Switzerland's 26 cantons have already decided to abolish their lump-sum rules outright or have toughened the criteria.

Swede Ingvar Kamprad, founder of global furniture giant Ikea, is one of the best-known beneficiaries of the lump-sum rules.

Kamprad, who lives near Lausanne in the canton of Vaud, was recently ranked by Swiss magazine Bilan as the richest man in Switzerland, with a net worth of up to 39 billion Swiss francs ($42 billion).

Ikea has insisted the sum mistakenly attributes to Kamprad personally the value of the unlisted, family-owned group, which has a complex ownership structure through several foundations.