Chinese top legislator Zhang Dejiang on Sunday pledged to enhance environmental legislation and oversight of pollutant emissions, as Beijing continued to be shrouded in a spell of lingering smog.

The top legislature will work to revise the Environmental Protection Law and the Air Pollution Prevention and Control Law to improve the environmental protection and management system, said Zhang, chairman of the National People's Congress (NPC) Standing Committee.

It is necessary to fully analyze the deep-rooted reasons for environmental problems and strive to fundamentally reverse environmental deterioration by improving laws and regulations, strengthening supervision over the process of environmental management, tightening oversight of the discharge of pollutants, and inflicting harsher punishments for illegal practices, he said.

The policy of compensation for ecological damage must be implemented, Zhang said, citing a principle that developers are responsible for protecting the environment and those who damage it must provide compensation.

His words came just days after Chinese Premier Li Keqiang "declared war" against pollution on Wednesday, and pledged to fight it with the same determination the country battled poverty.

Fighting pollution has long been on top of the government's agenda, but a spell of smog that enveloped some 15 percent of the country's territory a week ahead of the annual parliamentary session added urgency to the matter. Beijing at one point recorded "beyond index" measurements of particulate matter.

Revising the environmental protection law, which took effect in 1989, has been deemed central to curbing pollution. However, the past three attempts to amend the law have not been successful, with unsatisfied lawmakers calling for stricter measures and more government obligations.

It is quite rare in China for a law or amendment not to be passed after three readings. Another such rare case was the property law, which was finally passed in the fifth session of the 10th NPC in March 2007 after eight readings.

Zhang said prominent environmental problems, such as air, water and soil pollution, are of great public concerns and stressed that protecting the environment is an urgent and complex task that requires long-term efforts.

The NPC Standing Committee will investigate compliance with the Air Pollution Prevention and Control Law, carry out special investigations and studies on preventing and controlling soil pollution, exhort relevant departments to solve prominent environmental problems, and strengthen ecological conservation, he said.