Faced with lay-offs and wage cuts as falling demand in the West hits the country's vast manufacturing sector, the workers who have powered China's breakneck growth are refusing to go quietly.

Over the past month, thousands of factory workers in China's southern manufacturing heartlands have wrested concessions from employers facing shrinking exports and rising costs in a wave of labour unrest.

In the southern boomtown of Shenzhen, workers recently gathered at the office of labour rights organisation Little Bird to debate a possible strike at a factory that employs them to demand better overtime pay and compensation.

"We have never experienced this situation. We want to learn the different methods for protecting our rights," said Ran Lin, 30, who spends 11 hours a day, six days a week testing thousands of circuit boards on an assembly line.

Ran, who supplements his 2,000 yuan ($315) monthly wage by working overtime at the Hong Kong-invested Yong Jie Electronics factory, said the company had reduced perks such as meals and housing, even as the cost of living rose.

"We made contributions to economic development. We gave so much to the company. I hope they can give us suitable compensation," said Ran.

As a manufacturing slowdown forces employers to cut back on benefits and lay off staff, workers are reaching out to grassroots groups such as Little Bird and even government-linked agencies that offer legal advice and address complaints.

"Workers' recognition of protecting their rights has increased. They have learned to unify," said Wei Wei, founder of Little Bird.

Wei said the dense concentration of factories in China's southern province of Guangdong had helped spread news of past strikes, which has emboldened workers in a recent wave of labour conflicts.

Thousands of workers in Guangdong and elsewhere downed tools last month in a series of strikes as factories hit by slowing demand in the United States and Europe passed the pressure of rising costs and falling orders on to staff.

China's manufacturing activity contracted in November for the first time in 33 months, as the export-led economic growth moderated to 9.1 percent in the third quarter from 9.5 percent in the previous quarter due to falling demand.

China's ruling Communist Party fears an independent labour movement could threaten its grip on power, so it only allows only one, government-linked trade union.

But activists say government officials have been more sympathetic to individual grievances against factories, especially those funded by foreign companies or overseas Chinese investors from Hong Kong and Taiwan.

"The government is afraid of simmering grievances. They don't want workers to go on the streets or to demand trade unions," said Debby Chan of Hong Kong-based Students and Scholars Against Corporate Misbehaviour.

Authorities have addressed concerns of workers by giving more teeth to a revised labour contract law, consulting industry groups and allowing courts to handle disputes.

And in an apparent response to recent unrest, authorities in Shenzhen recently announced plans to hike the minimum wage by 14 percent to 1,500 yuan per month from January, following a 20 percent rise in April.

Geoffrey Crothall, a spokesman for the Hong Kong-based China Labour Bulletin, said some of the recent action showed a new level of sophistication.

He cited the example of workers at five Pepsi bottling plants across the country who protested on the same day after the US beverage giant sold its plants in China.

"That is a level of organisation that we've not really seen before, in terms of coordination of factories in different parts of China," Crothall said.

In strikes last year against Japanese companies, workers cloaked their protests in anti-Japanese rhetoric to make them more acceptable to the government, which still raises the issue of Japan's wartime atrocities.

"They know it's a motivating tool to get people on their side. Chinese workers are quite politically savvy," added Crothall.

At a Shenzhen factory owned by Hong Kong women's underwear maker Top Form International, last month hundreds of workers refused to return to their sewing machines for several days, until management paid every worker 1,000 yuan.

"They swear at us. They never give us overtime. Why should we work?" one of the strikers told AFP outside the ageing green factory building.

Another two-week strike in November by nearly 1,000 workers which paralysed a Shenzhen factory invested by Japanese watchmaker Citizen revolved around rest breaks.

Managers made employees work additional time without pay to make up for breaks, which lasted 15 minutes every two hours, workers said. They returned after talks negotiated 70 percent pay for the rest periods.

Deng Shiping, who joined a strike of thousands against a Taiwan-invested electronics factory last year, said organising was made easier since everyone lived together in dormitories -- a typical arrangement for migrant labourers.

Workers chose representatives to inform other shifts and departments about the planned strike. "There was no leader, it was us -- the workers -- all together," he said.