THE richest one per cent of the UK population now owns more than 20 times the total wealth of the poorest fifth, making the country one of the most unequal in the developed world, according to an analysis by Oxfam.

The figures suggest that around 634,000 Britons are worth 20 times as much as the poorest 13 million and the charity urged Theresa May to take action to close the gap between the "haves" and the "have nots".

Oxfam's report suggested that the massive inequality in British society contributed to the vote to leave the European Union and called for sweeping reforms to big business.

"The UK is one of the most unequal developed countries in the world,” declared the report. “Three decades of high-level inequality have had a profound impact, leading many people to believe that they have little stake in society and to feel locked out of politics and economic opportunity.

"Whatever your views on Brexit, the referendum brought divisions within our country to a head, with many people expressing distrust and disconnection with political processes and voting for change in the hope that it would improve their economic position," it said.

The Oxfam report used data from Credit Suisse which showed the richest 10 per cent of the UK population owned more than half of the country's total wealth, some 54 per cent, with the top one per cent owning nearly a quarter, 23 per cent, while the poorest 20 per cent shared just 0.8 per cent of the country's wealth between them.

The paper welcomed the Prime Minister's recognition of the need to shake-up corporate culture and suggested a four-point action plan for her to adopt.

The measures included: delivering on Mrs May's pledge to give a greater voice to workers through greater representation on company boards; adopting pay ratios to curb excess salaries at the top and tackle low wages at the bottom and tackling corporate tax avoidance and end UK-linked tax havens.

A UK Government spokeswoman insisted work was still the best route out of poverty and pointed out that since 2010 some 2.7 million more people had a job.