In the 2003 District Council election, he won a seat in the Wang Yat constituency, taking the first seat for the Democrats in Tin Shui Wai. In the 2004 Legislative Council election, he ran in the New Territories West with Albert Ho's ticket. Ho eventually won a seat but Cheung was unelected. He ran again in 2008 Legislative Council election, leading the third ticket for the Democratic Party along with Albert Ho and Lee Wing-tat. His ticket received 10,069 votes and was not elected.
