Hong Kong police ordered defiant protesters to disperse from the city's main pro-democracy site or face arrest Thursday, in a final showdown as they dismantled rallies that have lasted for more than two months.

Bailiffs had already moved in to remove barricades around the protest camp in the heart of the business district, but despite the police order a hard core of a few hundred refused to leave.

Crowds shouted demands for free leadership elections -- a cause which has underpinned the demonstrations -- and vowed the clearance operation would not end a campaign they say has redefined the city's vexed relationship with Beijing.

Police announced a "lockdown" of the area after a 30-minute window in which protesters could voluntarily leave the site -- an encampment of tents, supply stations and art installations sprawling along a kilometre of multi-lane highway.

"Police will lock down the occupied area and set up a police cordon area... If anyone refuses to leave police will take action to disperse or arrest," said senior officer Kwok Pak-chung.

Thousands gathered on Wednesday night for one final mass rally at the Admiralty site, but the numbers had dwindled by morning, leaving just a few hundred sitting in the road, including pro-democracy lawmakers.

"This is not the end of the movement. The political awakening amongst the young is irreversible and we will fight on," pro-democracy lawmaker Claudia Mo told AFP earlier Thursday.

The bailiffs who descended with cutters and pliers to take down barricades and load them into trucks were serving court orders taken out by transport companies frustrated at the long-running disruption.

Many protesters had packed up their tents and left by Thursday morning, but left hundreds who said they intended to stand their ground.

"I'm not tired (of the campaign). I'll never be tired, only the government is tired," said 19-year-old student Alice.


'The start of something'

The Admiralty site has been the focal point of the protest movement since rallies erupted in September, after China's Communist authorities insisted that candidates in Hong Kong's 2017 leadership election will have to be vetted by a loyalist committee.

Protesters say this will ensure the election of a pro-Beijing stooge, and their struggle has highlighted a litany of frustrations in the former British colony including a yawning income gap and lack of affordable housing.

Some in Admiralty expressed a sense of failure, after the authorities in Hong Kong and Beijing refused to give any concessions on political reform, but said that the occupation had changed Hong Kong for good.

"I feel sad because we haven't achieved our mission, but I think there can be progress in the future," said 23-year-old welfare worker Dubi. "I think it's the start of something long-term."

Protesters were joined by more than 20 pro-democracy lawmakers and other prominent figures ahead of the police action.

Media mogul Jimmy Lai, a fierce critic of Beijing, said he would stay at the site "until I am arrested".

"Definitely you will miss the people you have spent over two months with, other than that we're looking forward to the next one," he said, referring to future actions for the movement.


'Resolute action'

Authorities had warned they would take "resolute action" against those who resist the clearance which they say is being carried out to restore public order and reopen roads to traffic.

Student protest leaders have encouraged demonstrators to stay at the Admiralty site to face police but have urged non-violence.

There are fears that radical splinter groups will dig in for a final stand, following violent clashes outside government headquarters at the end of last month.

But many said they did not want a confrontation.

"I'll probably leave just before the action because my job would be difficult if my name was recorded by police," said a 29-year-old surnamed Chow who works for a civil society group.

At their height, the protests saw tens of thousands take to the street, but public support has waned in recent weeks.

Student leaders and lawmakers addressed an emotional crowd Wednesday night while many took photos of the site which has become a cradle of creativity, adorned with statues and artworks.

"For me, the protest has been a good thing," said 28-year-old finance worker Jacqueline Au.

"It's a wake-up call for the government in China that it's not that easy to impose the Chinese system in Hong Kong."