BEIJING -(Dow Jones)- China's gross domestic product growth is likely to decline in the second quarter, Cheng Siwei, and influential former Chinese lawmaker, said Sunday.

Government support measures will likely keep the full-year growth rate at around 8%, but could also push up inflation to 4% to 5%, he said at a forum.

China's gross domestic product in the first quarter grew 8.1% from a year earlier, decelerating from a growth of 8.9% in the fourth quarter and 9.2% growth for the whole of 2011.

Meanwhile, the consumer price index rose 3.4% from a year earlier, down from 3.6% in March.

-Yue Li contributed to this article; Dow Jones Newswires; (8621) 6120 1200; yue.li@dowjones.com