A group of around 300 millionaires, economists and political representatives have written an open letter to the G20 member countries advocating an increase in taxes on the richest individuals in order to combat inequalities and "prevent extreme wealth from eroding" the collective future.

"The accumulation of extreme wealth by the world's richest individuals has become an economic, ecological and human rights disaster, threatening political stability in countries around the world. These stark levels of inequality undermine the strength of virtually all our global systems and must be tackled head on," say the signatories in an open letter, among them Abigail Disney, Disney heiress and philanthropist, the former leaders of Romania, Croatia, the Czech Republic and Bulgaria, MEP Aurore Lalucq, US Senator Bernie Sanders, artists Brian Eno and Richard Curtis, the former president of the UN General Assembly, Maria Espinosa, and economists such as Gabriel Zucman, Jayati Ghosh, Kate Raworth, Jason Hickel, Lucas Chancel and Thomas Piketty.

"Decades of tax cuts for the richest, based on the false promise that wealth at the top would somehow benefit all of us, have contributed to the increase in extreme inequality," they point out in the letter organized by various organizations, including the humanitarian organization Oxfam, quoted by the Eco Online portal, adding that political choices have allowed the richest "to continue to use tax havens and enjoy preferential treatment, to the extent that in most countries of the world they pay lower tax rates than ordinary people."

"We cannot allow extreme wealth to continue to erode our collective future," they declare in the document, calling on the member states of the G20, the world's most industrialized nations, to increase taxes on the richest individuals, "through a truly inclusive and ambitious international collaboration to tax wealth and prevent competition and tax evasion by the richest people."

According to the signatories, the aim is to create "new tax regimes - at national and international level - that eliminate the ability of the ultra-rich to avoid paying their debts and introduce new rules that determine greater taxation of extreme wealth", they reiterate, listing that such an agreement would make it possible to combat inequalities, as well as to raise the essential funds "to tackle the multiple challenges facing the world".

It should be remembered that Spain - which belongs to the G20 through the European Union and not as an individual country - this year introduced a new "solidarity tax" on large fortunes of more than three million euros, which will be in force until at least 2024, and which the Spanish government justifies with the need to finance the response to the crisis generated by the war in Ukraine and inflation.

In the letter, the signatories also warn that "for the first time in decades, extreme poverty is on the rise and almost two billion people" live in countries where inflation does not compensate for wage increases, causing a loss of purchasing power. "In addition, time is rapidly running out for countries to make the necessary green investments that would align with the 1.5 degree warming limit called for in the Paris Agreement," they warn.

According to data from the humanitarian organization Oxfam, in the last decade billionaires have seen their fortunes more than double, from 5.6 billion dollars to 11.8 billion dollars. The fortunes of billionaires are increasing by 2.7 billion dollars a day, at a time when the world is being affected by a crisis of rising living costs, inflation and rising interest rates.

In the last 10 years, millionaires with fortunes of more than 50 million dollars have seen their wealth increase, while billionaires have seen their wealth soar by 109%. Only 4 cents in every dollar of tax revenue comes from wealth taxes, Oxfam adds.