Student activists were on Thursday set to end their three-week occupation of Taiwan's parliament, but they vowed to press on with their bid to stop the government ratifying a contentious trade pact with China.

The demonstrators began dismantling the huge stacks of armchairs they used to barricade themselves in when they seized the chamber on March 18, in the first such occupation of Taiwan's parliament in the island's history.

By midday the dozens of remaining protesters -- whose numbers have dwindled from the 200 who initially stormed the building -- had packed up their sleeping bags, taken down the posters they had plastered all over the chamber, and even repainted the walls.

"We're doing the final clean-up of parliament. Everything should be done by 4:00 pm," Shih Yen-ting, a spokesman for the protesters dubbing themselves the "Sunflower" movement, told AFP ahead of the departure scheduled for 1000 GMT.

"We're putting the final touches on our exit."

Outside parliament, the protesters -- who oppose a trade pact that they say will damage their economy and leave Taiwan vulnerable to political pressure from Beijing -- were seen taking down their tents and posters, and hosing down the roads.

The activists will hold a simple ceremony half-an-hour before their departure to mark an end to the sit-in, Shih said.

"We'll make it clear to our supporters that this is not the end, but the beginning of the next stage of our work," the 25-year-old added.

The sit-in comes to an end after parliament's speaker Wang Jin-pyng pledged not to preside over further debate on the trade pact until a law has been introduced to monitor such agreements with China -- a key demand of the protesters.

But they have vowed to push on with their campaign to force the ruling Kuomintang party to retract the trade deal, a demand which President Ma Ying-jeou has flatly rejected.

The protest drew large crowds of supporters, with more than 10,000 gathered outside at one point.

There were violent clashes on March 23 when baton-wielding police turned water cannon on other protesters who had stormed the nearby government headquarters.

On Thursday, Shih described the atmosphere in the chamber as "relaxed" compared to the angry storming of the parliament three weeks ago.

The pact is designed to further open up trade in services between China and Taiwan, which split 65 years ago after a civil war.

Ma, who has pursued closer ties with China since coming to power in 2008, has said failure to ratify the deal would be a grave setback to Taiwan's efforts to boost trade.

The deal is a follow-up agreement to a sweeping Economic Cooperation Framework Agreement signed in 2010 to reduce trade barriers between China and Taiwan.

Ma has overseen a marked thaw in relations with Beijing since he came to power pledging to strengthen trade and tourism links.

He was re-elected in January 2012 but is battling to shore up his popularity, with his approval ratings currently sitting at around only 10 to 15 percent.

China still considers Taiwan as part of its territory awaiting reunification -- by force if necessary.