Having served as police, deputy magistrate, and Sham Shui Po District Councillor, Lau was arrested in 2020 for joining pro-democracy primaries as one of the Hong Kong 47.

Having joined the Royal Hong Kong Police Force,[1] he then worked for Allen Lee, founding chairman of Liberal Party, of writing speeches until the late 1990s.

On 30 May 2024, Lau was one of two defendants who were acquitted, the other being Lee Yue-shun, because the court found that he had not mentioned an intention to veto the budget or subvert state power.

[9] While tried for subversion, Lau continued representing Tong Ying-kit in Hong Kong's first national security trial in 2021.

In September 2021, Lau was unseated from the Sham Shui Po District Council after his oath of loyalty pledging allegiance to the Hong Kong Government was ruled invalid by the authorities.