The number of migrant workers in China's national legislature has sharply increased from three to 31 in the past five years, showing the growing importance of this particular group of workers.

Five years ago, migrant workers made their first appearances as deputies at the first annual session of the 11th National People's Congress (NPC).

Most migrant workers in China are former farmers who left their villages to work in cities amid the country's urbanization boom. They currently number 260 million.

Migrant workers have become an important part of Chinese society, as they comprise more than one-third of the country's labor force, said Cai Fang, head of the Institute of Population and Labor Economics under the Chinese Academy of Social Sciences.

"They have contributed a lot to China's economic growth and they have their own interests, difficulties and needs," said Cai, who is also a deputy in Beijing to attend the first annual session of the 12th NPC.

Living in cities but lacking urban household registration accounts, migrant workers lag behind their urban peers in terms of social security, healthcare services and education for their children.

For them, having a greater representation in the NPC will help them express their opinions and requests, Cai said.

Last November, 26 migrant workers attended the 18th National Congress of the Communist Party of China (CPC) as delegates, also attracting great attention.

Zeng Xianggui, a 33-year-old who was a waitress before becoming a trade union leader at a property management company, bought a new digital voice recorder before heading to Beijing to attend the national legislative session.

The novice lawmaker would like to record what other deputies say during discussions, as well as what she says during the session and in interviews.

"I can review how others behave and how I behave so I can improve my performance," she said. "As a deputy, I need to be able to express myself clearly."

The mother of a four-year-old is most interested in education issues, and she plans to put forward a proposal on allowing the children of migrant workers to enjoy free compulsory education, regardless of their household registration locations.

As one of the first three migrant worker deputies to the 11th NPC and the only one re-elected this year, Zhu Xueqin still remembers how shy she was five years ago, when she was surrounded by reporters at the entrance to the Great Hall of the People.

Now, she speaks with composure and confidence in the limelight.

Over the past five years, Zhu has submitted proposals and motions concerning the income of migrant workers, their pension programs, medical services, vocational training and education, as well as work-related disease prevention and treatment.

When the NPC is not in session, she takes part in inspection tours and meets with government officials, prosecutors and judges, which gives her a deeper understanding of Chinese society.

"An NPC deputy is on duty 365 days a year, not just once a year, when they attend the session," she said. "I learn a lot about laws and how to protect the interests of my fellows with the law."

For the first time, the new national legislature was elected using the equal population ratio for both rural and urban areas.

Each rural NPC deputy represented a population eight times that of an urban deputy from the 1950s through the 1990s, when the country had a mostly rural population.

Due to fast urbanization, the representation ratio fell to 4:1 after the Electoral Law was revised in 1995 and further dropped to an equal 1:1 under the 2010 amendment.

According to the National Bureau of Statistics, China's urban population increased by 20.96 million annually from 2002 to 2011, with about 51.3 percent of Chinese living in cities by the end of 2011.