Green party calls for wealth tax on assets of multimillionaires

The Green party has called for a wealth tax of up to 2% on the assets of multimillionaires that it believes could raise more than £40bn a year.

Presenting the radical new proposal, Natalie Bennett, the Green leader, said other political parties only offered minor tweaks to the UK's failed economic system, instead of major changes to deal with inequality.

The party said the tax would affect around 300,000 people with assets of more than £3m – the richest 1% of people in the UK. In a report on possible rates, it suggested the tax could be set between 1% and 2%, which would raise £23bn at the lower end or up to £43bn at the higher end of the spectrum.

The report points out that wealth taxes of different kinds are already in place in France, Spain, Iceland, the Netherlands, Norway and Switzerland. It also cites the work of French economist Thomas Piketty, who has found that the rate of return on capital outstrips the rate of growth and that inherited wealth will therefore always grow faster than earned income.

Piketty's much-discussed new book, Capital in the 21st Century, is on Labour leader Ed Miliband's reading list. Miliband has said inequality is the defining problem of modern times.

The wealth tax policy is one of a number of offers from the Greens, whose pledges also include re-nationalising the railways, bringing in a living wage, capping bankers' bonuses, opposing austerity and scrapping the welfare cap.

Bennett said the party is the only one committed to progressive policies that tackle Britain's problem with inequality, helping it to gain more votes than the Liberal Democrats in May's local elections.

"Our strong general election polling and surge in membership goes to show that the Green party's commitment to people over profits policies are really hitting home," Bennett said. "The Green party is prepared to take principled stands and an increasing number of voters recognise and value this."

The party said the UK's richest 1,000 people have doubled their wealth in the last five years, while the number in poverty and resorting to food banks has risen. It also mentioned an analysis by the Equality Trust that has found the richest 1% of Britons has the same amount of wealth as 54% of the rest of the population.

The Greens are polling roughly equally with the Liberal Democrats at the moment, and claim the party's membership has risen by almost a quarter in the last five months.

The party's only MP is Caroline Lucas, the member for Brighton Pavilion, but the party is hoping to challenge Stephen Williams, the Liberal Democrat MP for Bristol West, where it gained a slight poll lead in May.