Hong Kong (AFP) - Hong Kong's embattled leader faced mounting pressure on Friday to abandon a deeply unpopular plan to allow extraditions to China, with protest organisers getting police go-ahead to hold a new rally at the weekend.

The international finance hub was rocked by the worst political violence since its 1997 handover to China on Wednesday as tens of thousands of protesters were dispersed by riot police firing tear gas and rubber bullets.

The city's pro-Beijing leader Carrie Lam has so far refused to meet protester demands to withdraw or scrap the bill -- although rumours were swirling Friday that a postponement of the bill was imminent amid a growing chorus of discontent.

Throughout the day Lam found herself facing calls from within her own political camp to reverse course and tamp down spiralling public anger -- including from hardline pro-Beijing lawmakers.

"Shouldn't (we) cool the citizens down? I think to postpone it for a little bit is not a bad thing. At this moment, the government should self-examine," Ann Chiang, a hardcore pro-Beijing lawmaker, told i-Cable News.

Friday's comments marked the first indication that supporters of the extradition law are now having second thoughts, following a growing public backlash.

"The momentum against the bill is growing," said Hong Kong-based political analyst Willy Lam.

"The opposition to the bill now includes powerful members of the business community, former senior civil servants and the foreign business community -- so I think Xi Jinping is under heavy pressure to postpone the bill, and the scapegoat will be Carrie Lam."

Prominent pro-Beijing lawmaker Michael Tien also openly called on Lam to postpone the bill.

"She would gain points instead of losing points," he told reporters.

"Nothing is ever too late. New situations arise that would provide the basis for any leader to change their position. There's nothing wrong with that."

Tien's comments came as Lam's own advisor said pushing ahead with fast-tracking the bill through the city's legislature had now become "impossible".

"Personally I can see that it is impossible to discuss (the bill) when there is so much conflict on all sides. It is very difficult," Bernard Chan told RTHK radio.

Chan sits on the Executive Council -- the equivalent of a cabinet -- and was appointed by Lam two years ago to be a top advisor.

Backlash

Opposition to the extradition bill has united an unusually wide cross section of Hong Kong against the proposal and sparked huge rallies.

On Sunday, protest organisers said more than one million people came out for the largest demonstration the business hub has seen in decades.

Protest leaders met with police Friday to discuss their plans for another mass rally on Sunday, which was approved after several hours of discussion.

The prospect of another protest raises the chance of fresh confrontations with the government following unprecedented political unrest.

Leading democratic figures said only the complete withdrawal of the bill would stop future protests and calm public anger.

"We can't trust the pro-establishment lawmakers," said pro-democracy legislator Alvin Yeung. "We could only accept the government's withdrawal plan."

Lam's determination to press ahead with a debate on the proposed law in parliament on Wednesday sparked another huge protest that descended into violence and brought the city's commercial district to a standstill.

Young Hong Kongers, angered by years of sliding democratic freedoms in the city, have been at the forefront of the protests.

But the extradition plan has also received a barrage of criticism from legal bodies, business groups, religious figures and Western nations who fear the proposal would tangle both locals and foreigners up in China's politicised and opaque courts.

China's ambassador to Britain, Liu Xiaoming, has rejected claims that Beijing was behind the extradition bill, telling the BBC that the "Beijing central government gave no instruction, no order.... This amendment was initiated by the Hong Kong government."

"Beijing is saying that it was never Beijing's intention to push the bill, it was Carrie Lam's intention -- so Carrie Lam has to bear the responsibility," added analyst Lam.