A women's studies expert has called for a law on domestic violence to provide better protection for victims of this "increasingly common" social ill.

Sun Xiaomei, an NPC deputy and professor at the Chinese Women's College, said: "Domestic violence is a social phenomenon that crosses all social strata and is becoming more and more common. There is an urgent need for legislation."

Since 2005, the All-China Women's Federation has been getting about 40,000 complaints a year relating to domestic violence. In 2000, the number was just 2,000, she told China Daily.

The number of serious cases, in which women and children are badly beaten or even killed, is also on the rise, she said.

"Society is well aware that domestic violence exists, but there are no guidelines in law to clarify when judicial departments can get involved or how the perpetrators should be punished," Sun said.

In her proposal, Sun has called on the NPC to draft legislation within its next five-year term to provide a clear definition of the crime and details of how it should be punished.

She said the law should also acknowledge the role of social organizations in providing refuge, and giving guidance and assistance to victims of domestic violence.

One of China's leading scholars on women's studies, Sun has been at the forefront of promoting women's rights for more than 20 years.

She first called on the law to pay more attention to domestic violence in 1998, after conducting a survey of 4,000 people on marriage and the family. Two years later, an amendment to the law on marriage incorporated the term "domestic violence" for the first time on China's statute books.

Over the past five years, Sun has pushed for "preferential support" for the role of women in legislative and administrative affairs. In that time, the proportion of women deputies within the NPC has risen by a full percentage point.