China's National People's Congress (NPC), the country's annual parliament, which is scheduled to hold its latest session next week is commonly known as the Millionaires' Club because of the wealth of some of its members. But the Billionaires' Club is now perhaps more appropriate, after a new report showed wealth in the legislature has ballooned.

The net worth of the 70 richest delegates rose to 565.8 billion yuan (£67bn) last year, a remarkable increase of £7.25bn from 2010, according to figures from the Hurun Report, which counts China's wealthy and analyses what they do. The richest 2 per cent of the NPC had an average wealth of £880m per person.

The annual gathering in the Great Hall of the People has all the trappings of a Marxist-Leninist talking shop, where delegates approve with large majorities bills from by the Communist Party's upper echelons.

It is now more than a decade since those working in the private sector were first invited by the Communist Party to take part in the NPC. Now delegates include a who's who of China's capitalist elite. Zong Qinghou, the country's second richest man and the head of the drinks company, Hangzhou Wahaha Group, with a fortune of 68 billion yuan (£6.8bn), is one such member.

Another is Wu Yajun, chief executive of the Beijing-based property developer Longfor Properties. Her family wealth is estimated at 42 billion yuan (£4.2bn), according to the Hurun Report. The ever-growing wealthy class in China included 960,000 millionaires in 2010, a rise of 9.7 per cent over the previous year. Chinese economic growth was 9.8 per cent at the end of 2010, and per capita GDP has more than doubled since 2000, according to the World Bank figures.

Many of the richest taking part in the NPC meeting are part of the growing property sector at a time when there is great unease in China about a possible bursting of the property bubble in the main cities.

"Stability will be prioritised in this crucial year for China. Yet China still pins a great deal of its hope to economic growth to further its development across the board," the Xinhua news agency said in a commentary.

"Moreover, the widening gap between the rich and the poor, along with urban-rural and regional discrepancies, is resulting in more social tensions," it said.

Money and power: The billionaire politicians' club

Zong Qinghou: Reputed to be acutely dutiful, Mr Zong says he oversees all office expenses and is said to live on a modest $20 (£12.60) a day.

Wu Yajun: Having worked at a factory and as a journalist, Ms Wu moved to property development, founding Longfor Properties with husband Cai Kui.