A senior Hong Kong lawmaker was expelled from a prestigious Chinese government body Wednesday, in a sign that Beijing will not tolerate dissent from loyalists over pro-democracy protests in the semi-autonomous city.

James Tien had his "qualifications revoked" as a member of the Chinese People's Political Consultative Conference (CPPCC), the state-run China News Service said.

The prominent businessman and politician had criticised Hong Kong's embattled leader Leung Chun-ying for failing to put an end to more than a month of pro-democracy protests -- an unusual move for a pro-Beijing lawmaker.

The CPPCC voted to pass the "decision on revoking Tian Beijun's membership in the 12th Chinese People's Political Consultative Conference", the government body said, using Tien's name in Mandarin and without providing further details.

In a brief statement Tien said he accepted the CPPCC ruling and would resign as leader of Hong Kong's pro-business Liberal Party.

"I just remembered I am a lawmaker in Hong Kong, neglecting my role as a CPPCC member. Maybe that was inappropriate," Tien said of his comments about Leung.

But he insisted later he would not withdraw his comments.

"I see no reason for me to retract my statement or change my position... I speak from the bottom of my heart anyway," Tien told a press conference.

Demonstrators have staged street rallies and road blockades for more than a month, calling for free leadership elections for the former British colony in 2017.

The demonstrations present the most concerted challenge to Beijing's authority since the bloody 1989 Tiananmen protests.

Tien's younger brother Michael, another Hong Kong lawmaker, told AFP before the announcement that his brother was being punished for perceived disloyalty to Leung.

"The decision is definitely based on my brother's comments about CY (Leung Chun-ying)," Michael Tien said.

James Tien said last week that Leung should consider resigning for failing to halt the protests.

"Residents are ignoring court injunctions (to disperse) and pan-democrats are being uncooperative. How is he going to govern?" Tien said on Friday, according to the South China Morning Post.

Despite hailing from Hong Kong's pro-Beijing camp, the 67-year-old politician is no stranger to ruffling political feathers.

In 2003 he withdrew his party's support for a government-backed national security bill amid large street protests, leading to the legislation's collapse and the eventual resignation of Hong Kong's then-leader Tung Chee-hwa.

He backed Leung's opponent Henry Tang in the 2012 race to be the city's chief executive.

- Leung increasingly unpopular -

Leung's popularity has taken a nosedive since the protests began last month.

A poll this week by the Chinese University of Hong Kong showed he now has a 38.6 voter approval rating on a 0 to 100 approval scale -- his lowest since taking office in July 2012, when he scored 53.9.

A hate figure among protesters, who are calling for him to resign, Leung stirred fresh anger last week when he said that open elections were not feasible because they would result in the city's poor dominating politics.

The demonstrations were sparked by China's decision that all candidates running for the top Hong Kong post in 2017 must be vetted by a loyalist committee, a decision which the protesters say will result in the election of a pro-Beijing stooge.

China has refused to budge in the face of the rallies and has publicly thrown its full support behind the Hong Kong administration.

Tien's brother said the central government had little tolerance for dissent at such a crucial time.

"President Xi (Jinping) himself has openly announced and had asked for all the support. The timing is crucial," said Michael Tien, adding that Beijing leaders expect the city's establishment politicians to support Leung "wholeheartedly".

"If there is any change at this moment (within the city leadership), the Occupy movement is going to turn into a severe, ugly crisis... they need CY Leung to stay here and resolve the crisis," he said, referring to the protests known as Occupy Central.

The CPPCC is a discussion body that is part of the Communist party-controlled governmental structure.