Television and radio stations can express their opinions in programmes, but must alert the audience that what they are about to hear is an editorial and give airtime to those with other views, advisers to the broadcasting watchdog recommended.
Members of the Communications Authority's broadcast codes of practice committee agreed unanimously yesterday that there should be clear rules on what it calls editorial programmes - in which a broadcaster expresses its view on public policy or other matters.
The watchdog launched a consultation in December after a flood of bias complaints; free-to-air broadcaster ATV's ATV Focus was the subject of 42,000 complaints in 2012, while rival TVB's show Scoop was subject to 25,000 bias complaints last year.
Committee chairman Raymond Roy Wong said it had recommended that broadcasters be subjected to new conditions.
"Before they air an editorial programme, they must audibly inform the viewers or listeners that the following programme is in fact an editorial programme stating the licensee's stance," he said.
"By the same token, if it was an editorial programme, they must provide ample opportunity on the same platform for those who do not agree with them [to air their views]."
The committee recommends defining editorial programmes as programmes in which licensed broadcasters and people exercising control over stations put forward their views. That could include directors, principal officers or the controllers of large numbers of voting shares in a station.
But he hinted that Commercial Radio host Stephen Chan Chi-wan may not be caught up by the rules. Chan was the station's chief executive until last month, when he took on the role of chief adviser, in part because he feared falling foul of new rules on bias.
An adviser may influence top executives but would not exercise control, Wong said when asked about Chan's situation.
The three-month consultation, which ended last month, received 127 submissions. A majority favoured treating editorial programmes in the same way as programmes in which hosts are given the opportunity to put forward their own views.
The issue came to a head after ATV Focus was subject to 42,000 complaints - out of the total of 47,000 received by the watchdog for 2012 - for claiming student protests against national education in schools were being manipulated by "destructive" politicians, backed by the West. The station was reprimanded and fined for the broadcasts.
Last year, 25,000 people complained about TVB's Scoop, which covers entertainment news and current affairs, for bias in coverage of the debate on new free-to-air television licences. It was accused of treating Hong Kong Television Network, which missed out on a licence, unfairly.
Under the proposed new rules, stations would have to provide a "suitable opportunity" for people holding different views to express an opinion, either on the programme the editorial ran on or on similar shows targeting a similar audience within an appropriate timescale.
Running an online forum for people to express their views would not be acceptable, Wong said, as "those who watch TV are not necessarily the same ones who would go on the internet."
The authority has yet to consider the recommendations or discuss a timescale for their implementation.