Lawyers are asking the government to stop broadcasting political advertisements on TV and radio because it violates the Broadcasting Ordinance.
Recently, the government had started broadcasting the "Your Vote. Don't cast it away" campaign, seeking support for its electoral reform.
Under the Ordinance, a licensed radio or television station must not air any ads of a political nature.
But under a code of practice on television advertising, government "announcements in the public interest", or APIs, are not considered advertisements.
Progressive Lawyers Group, a group made up of more than 40 barristers, solicitors and law students, thinks the government is exploiting this legal loophole to allow these political ads to be on TV and radio.
"Broadcasters are required, as a licensing condition, to air all APIs the government gives them. By dressing up political ads as APIs and requiring broadcasters to air them, officials are forcing the broadcasters to break the law," said Kevin Yam Kin-fung, convenor of the group.
A government spokesman said the announcements were meant to "promote the policy objective" to implement universal suffrage for 2017, which was its "constitutional responsibility".