The labor authority is working toward legally ensuring migrant workers are paid on a monthly basis.

Migrant workers are often paid according to a project's progress or even annually, but delays in paying wages have been too frequent over the past year, Qiu Xiaoping, vice-minister of human resources and social security, told China Daily.

Declining export demand and cash flow problems have hit many sectors that employ migrant workers, but the worst-hit sector was construction, Qiu said.

More than 300 cases of delayed wages were reported in 2012, Zou Zhen, director of the social security department under the All-China Federation of Trade Unions, said at a news conference on Dec 20.

Qiu said that workers must get their full pay on a monthly basis.

"The Labor Law stipulates that employers, regardless of what industries, should pay workers their wages on a monthly basis," he said.

Laborers are not hired directly by the construction company but through a third party that hires them out to sites. This creates another tier that often adds to the payment of wages being delayed.

A report by Beijing Normal University showed that only 33 percent of construction workers in the capital have signed labor contracts.

It is common practice in the construction sector for payment to be deferred until a certain phase of a project is completed.

This can create a chain of delayed payments, with contractors waiting for funds to be released before they can pay the subcontractor.

But Qui said that regardless of the procedures, contractors have a duty to pay their workers and should come up with a system to make sure this happened.

"Contractors should not pass on their difficulties to workers, and they should pay workers regardless of when they are paid," Qiu said.

Lu Qingcai, 36, is a migrant worker who has worked at a construction site in Jiujiang, Jiangxi province, for nearly a year.

"The contractor had promised to pay us, around 50 workers, wages for six months in June, but we got just 80 percent. We have yet to receive the rest, which is around 300,000 yuan ($48,000)," he said.

Lu said the contractor later promised to pay the remainder with the January wages.

"We hope he keeps his word. Wage delays are common, and I'm used to it.''

Qiu said the government will make greater efforts to enforce the implementation of laws and regulations.

He also promised strengthened supervision.

The Ministry of Human Resources and Social Security and five other ministerial-level departments started a two-month campaign on Nov 26 to deal with wage delays.

Labor authorities will fine companies that pay late.

Wage delays, if caused by malicious intent, were categorized as a crime last year, and about 80 people have been held on charges related to wage delays, China Central Television reported. Malicious intent is legally defined as employers transferring capital to avoid paying workers or actually refusing to pay.

The ministry will also strengthen efforts to enforce a mechanism that includes making the contractor put aside a sum equal to 3 percent of the cost of the project into a bank account. The government will manage the account and the money will be used to pay workers if wage delays occur. The mechanism also stipulates a general contractor's responsibility if its subcontractors delay paying workers.

Meanwhile, Zou Zhen, the union official, said his organization will cooperate with labor and construction authorities to improve employment relations and clarity in the complex contracting mechanisms.

"We will work to ensure that workers are covered by labor contracts," he said, "Individual contractors should be completely prevented from employing workers."

Contact the writer at chenxin1@chinadaily.com.cn