Often derided as a rubber-stamp legislature, the congress and its companion advisory body have in recent years become a club for some of China’s wealthiest executives, keen to rub elbows with government officials. Holding such high office also brings prestige and, much like peerage or knighthood in Britain, is seen as a marker of status in the Communist Party-dominated establishment. In China, it is sometimes known as “wearing the red hat.”

“People within the system can trade interests,” Zhang Ming, a political scientist at Renmin University in Beijing, said by telephone. “Whoever gets elected will have a pass to do so.”

Serving as a lawmaker has become so attractive to the wealthy that last year, of the 1,271 richest Chinese people tracked by the Shanghai-based Hurun Report, a record 203, or more than one in seven, were delegates to the National People’s Congress or its advisory body. The richest person that year among all three branches of the United States government, Representative Darrell Issa of California, would only rank as the 166th richest if he were a Chinese lawmaker.

“For reasons that don’t make sense to outsiders given the ‘rubber stamp’ nature of the N.P.C., membership in any honorary body is coveted by people who see it as a mark of social status, something to add to their resumes,” said Suzanne Pepper, a scholar based in Hong Kong who studies Chinese elections.

Many of the expelled delegates are executives of private businesses or leaders of state-owned companies, rather than career politicians and military officers — who are also well represented on the body.

The vote-buying scandal in Liaoning has been brewing for at least five years, with hundreds of officials and lawmakers in its provincial bodies accused of engaging in the bribery, according to a report in Caixin, a well-regarded Chinese newsmagazine. The report, posted online on Tuesday, has since been taken off the internet.