China's new leaders aim to establish a "fair and unified" social security system by 2020, according to a senior lawmaker and scholar.

This will meet increasing public needs for pensions and medical care, reduce the widening wealth gap and boost social cohesion, he said.

Zheng Gongcheng, a deputy to the National People's Congress who has been extensively involved in the design of China's social security system for years, said a sound social safety net is an essential part of the nation's goal of setting up a prosperous society by 2020.