Roman Abramovich
Roman Abramovich reportedly spent £40,000 on sushi (Reuters) Reuters

Inequality in the UK is returning to levels not seen since Charles Dickens' time and extreme wealth is causing world poverty to increase.

Oxfam has said the money earned by the world's 100 richest billionaires would be enough to end world poverty four times over.

Its report, The Cost of Inequality: how Wealth and Income Extremes Hurt Us All, calls on the likes of Carlos Slim Helu, Bernard Arnault and Roman Abramovich to help end global poverty.

Last year, the world's 100 richest had a net income of $240 billion (£151 billion). The charity says this extreme wealth is contributing to poverty by being economically inefficient: "The levels of inequality now being seen are in fact economically damaging and inefficient.

"They limit the overall amount of growth, and at the same time mean that growth fails to benefit the majority. Consolidation of so much wealth and capital in so few hands is inefficient because it depresses demand.

"There quite simply is a limit to how many luxury yachts a person could want or own."

Oxfam says it wants to put an end to extreme wealth by 2025 and bring poverty back down to 1990 levels.

Jeremy Hobbs, executive director of Oxfam International, said: "We can no longer pretend that the creation of wealth for a few will inevitably benefit the many - too often the reverse is true.

Bill Gates
Oxfam praised the likes of Bill Gates and said the world's billionaires should follow his charitable example (Reuters) Reuters

"Concentration of resources in the hands of the top 1 per cent depresses economic activity and makes life harder for everyone else - particularly those at the bottom of the economic ladder.

"In a world where even basic resources such as land and water are increasingly scarce, we cannot afford to concentrate assets in the hands of a few and leave the many to struggle over what's left."

While Oxfam praised charitable billionaires such as Bill Gates and Warren Buffett, it says the rise of movements such as Occupy shows public anger over extreme wealth levels: "The decision of Bill Gates and Warren Buffett to give away their fortunes or to call for greater taxation of excess wealth is an example to the rest of the world's billionaires."

The report highlighted how much of the world's wealth is owned by so few; in China, 10 percent of the top earners take home 60 percent of the country's income. In the US, the share of national income going to the top 1 percent has doubled since 1980, to 20 percent.

Oxfam wrote: "Gandhi famously said 'Earth provides enough to satisfy every man's need, but not every man's greed'.

"We cannot afford to have a world of extreme wealth and extreme inequality. We cannot afford to have a world where inequality continues to grow in the majority of countries. In a world of increasingly scarce resources, reducing inequality is more important than ever."

Here's some of the world's richest people and what they spend their fortunes on:

Carlos Slim Helu and family - $69 billion (£43.5bn)

Slim Helu, from Mexico, is the world's richest man, according to the Forbes Rich List. He made his fortune in the telecom industry and is an active philanthropist, although how much he contributes is unknown. He was, however, named one of the world's biggest givers by Forbes after giving away $4 billion.

Bernard Arnault - $41 billion (£25.8bn)

France's richest man Bernard Arnault is the chairman and CEO of luxury brand LVMH (Louis Vuitton Moet Hennessy). According to Business Insider, he was one of the biggest art collectors of 2012. His collection includes works by Picasso, Andy Warhol, Henry Moore, Jeff Koons and Frank Serra.

Roman Abramovich - $12.1 billion (£7.6bn)

Russian Abramovich is well known for his extreme spending. He has spent over £1 billion on football club Chelsea, bought the world's biggest private yacht (163.5 metres long) for around $475 million (£300m). He also is reported to have spent £40,000 on a takeaway; he ordered £1,200 of sushi from Baku in London and then had it flown by private jet to Azerbajan for an estimated £39,000.

Mark Zuckerberg - $17.5 billion (£11bn)

Facebook founder Zuckerberg is the 35<sup>th richest person in the world and is one of the youngest at just 28. He is thought to have spent $700,000 flying on private planes last year. However, he also signed up to fellow billionaire Warren Buffett's Giving Pledge - promising to donate half his wealth to charity.

Al-Waleed bin Talal - $18 billion (£11.3bn)

The Saudi Arabian investments tycoon controversially offered $10 million (then £7m) to New York mayor Rudy Giuliani following the 9/11 attacks (Giuliani returned the cheque). He owns the largest private jet in the world, which comes complete with a Turkish bath, boardroom and concert hall and cost £240 million. He also owns a 280ft yacht formally owned by Donald Trump.