Tax the super-rich, ex-leaders tell G20

Former presidents and prime ministers have sent an open letter to current leaders of the world's 20 largest economies urging support for a global tax on billionaires, which they called a rare political opportunity.

The move comes as Brazil's G20 presidency, which put the proposal on the table in February, seeks to build support for a declaration at the group's finance ministers and central bank governors meeting later this month in Rio de Janeiro.

Signed by 19 Club de Madrid members, a forum of former leaders with over 100 participants, the letter praised US President Joe Biden's billionaire income tax proposal but called for joint cooperation to combat tax evasion by the wealthiest.

"A global deal to tax the ultra-rich would be a shot in the arm for multilateralism: proving that governments can come together for the common good," said the letter.

Among signatories from across the political spectrum were Chile's Michelle Bachelet, Sweden's Stefan Lofven, Spain's Felipe Gonzalez and Jose Luis Rodriguez Zapatero, France's Dominique de Villepin, Canada's Kim Campbell, Australia's Julia Gillard and South Korea's Han Seung-soo.

Brazil's proposal, crafted by French economist Gabriel Zucman from the independent EU Tax Observatory, calls for an annual 2 per cent levy on fortunes exceeding $1 billion, which could raise up to $250 billion annually from about 3,000 individuals.

While the communiqué from the latest G7 meeting in June said the group would continue collaborating with the Brazilian G20 presidency to enhance international cooperation and bolster efforts toward progressive and equitable taxation of individuals, some nations have already raised objections.

In May, German Finance Minister Christian Lindner said his country sees new components of a global tax agenda with great skepticism, while U.S. Treasury Secretary Janet Yellen said the United States could not support negotiations involving redistributing proceeds among countries.

France, Spain, Colombia, Belgium, the African Union and South Africa, which will assume the G20 presidency next year, have already supported the initiative.