The actor Michael Sheen, who has opted to scale back his Hollywood career to campaign against high-interest credit providers, was among those supporting the calls.
The hope is to create pressure for global action when leaders of the G20 group of nations gather for a summit in Buenos Aires in November. Byrne, who organised the first OECD global parliamentary conference on inclusive growth, said he believed global inequality was now at a tipping point.
If we dont take steps to rewrite the rules of how our economies work, then we condemn ourselves to a future that remains unequal for good, he said. Thats morally bad, and economically disastrous, risking a new explosion in instability, corruption and poverty.
In a sign of the concern about the accumulation of wealth in the hands of so few, the move has gained support from across the political divide.
George Freeman, the Tory MP and former head of the prime ministers policy board, said: While mankind has never seen such income inequality, it is also true that mankind has never experienced such rapid increases in living standards. Around the world billions of people are being lifted out of poverty at a pace never seen before. But the extraordinary concentration of global wealth today fuelled by the pace of technological innovation and globalisation poses serious challenges.
If the system of capitalist liberal democracy which has triumphed in the west is to pass the big test of globalisation and the assault from radical Islam as well as its own internal pressures from post-crash austerity we need some new thinking on ways to widen opportunity, share ownership and philanthropy. Fast.
Demands for action from the group include improving productivity to ensure wages rise and reform of capital markets to promote greater equality.
Danny Dorling, professor of geography at the University of Oxford, said the scenario in which the super-rich accumulated even more wealth by 2030 was a realistic one.
Even if the income of the wealthiest people in the world stops rising dramatically in the future, their wealth will still grow for some time, he said. The last peak of income inequality was in 1913. We are near that again, but even if we reduce inequality now it will continue to grow for one to two more decades.