• "Tax us, the rich, and tax us now," an open letter by the "Patriotic Millionaires said.
• The letter, published Monday, included actor Mark Ruffalo and heiress Abigail Disney among its signatories.

A group of over 150 millionaires are calling on the elite attendees of this year's World Economic Forum in Davos, to tax them more.

The group, known as "Patriotic Millionaires," published an open letter on Monday reiterating calls for the attendees of WEF to "acknowledge the danger of unchecked wealth inequality around the world, and publicly support efforts to tax the rich."

"Tax us, the rich, and tax us now," the letter said, which included actor Mark Ruffalo and heiress Abigail Disney among its signatories.

They explained in the letter that the inequality baked into the international tax system had created distrust between the people of the world and its rich elites.

To restore that trust, the group argued that it would take a "complete overhaul of a system that up until now has been deliberately designed to make the rich richer."

"To put it simply, restoring trust requires taxing the rich," the millionaires said.

They said that the WEF Davos summit didn't deserve the world's trust right now, given the lack of "tangible value" that had come from discussions at previous events.

Some of the millionaires even staged pro-taxation protests at Davos over the weekend.

Cost of living crisis

This latest call from the rich to be taxed more comes as rising prices ratchet up the cost of living for people around the world.

Patriotic Millionaires referred to an Oxfam brief, published Monday, which found a billionaire was minted every 30 hours during the first two years of the Covid-19 pandemic. Oxfam estimated that nearly million people could fall into extreme poverty at a similar rate in 2022.

Julia Davies, founding member of Patriotic Millionaires U.K., said that as "scandalous as it is that governments seem to be utterly inactive on dealing with the cost of living, it is equally scandalous that they allow extreme wealth to sit in the hands of so few people."

Davies added that "global crises are not accidental, they are the result of bad economic design."

'Race to the bottom' on corporate taxes

Speaking to CNBC's Geoff Cutmore on a panel in Davos on Tuesday, Oxfam Executive Director Gabriela Bucher said that last year's multilateral agreement proposing that companies pay at least 15% tax on earnings, did not go far enough.

The Organisation for Economic Co-operation and Development tax reform agreement was signed by 136 countries and jurisdictions in October, though it is yet to be implemented.

Bucher pointed out that if the agreed rate had been set higher, at 25%, as recommended by tax experts around the world, this would raise a further $17 billion for the developing world.

Bucher was also concerned that the agreement, at the current level, would see a "race to the bottom" for corporate taxes and that countries with higher rates might actually bring them down.

"There's a danger that we're not really using this important tool at this moment when we have so many competing crises," she said, referring to a hunger crisis in both the developing world and in wealthier countries because of the surging cost of living.

Bucher later went on to say that "you can accumulate as much wealth as you want, but if everything ends around you then it doesn't make much sense."