But the advertisements have been treated as 'announcements in the public interest' (API), and therefore have not cost organisers anything to have them aired. Under their licences, both networks must allot one minute each hour to government APIs.

But television executives yesterday demanded that the Broadcasting Authority review whether the promotions were legitimate APIs.

'It's a pure promotion of a commercial activity for which the public has to pay [to attend],' said Stephen Chan Chi-wan, assistant general manager of TVB.

'This is clearly by nature not an announcement in the public interest. It just so happens that the Hong Kong government underwrites the activity.'

But a spokesman for the Harbour Fest organisers said last night it was a non-profit event.

'All proceeds from ticket sales and commercial sponsorship will be ploughed back to offset the operating cost,' he said.

'The broadcast of the API is to enhance community awareness of such promotional efforts and to strengthen Hong Kong's international image.'

The television promotions will continue to be screened until the Broadcasting Authority makes a decision, but the networks have reserved the right to claim 'commercial fees'.

Mr Chan said both broadcasters would write to the authority.

The issue is the latest in a string of debates surrounding the three-week Harbour Fest, which is scheduled to start next Friday and is one of several projects under the government's 'economic relaunch' campaign following Sars.

Legislators have criticised the government for pledging to pay for the event's estimated $80 million in losses if only half the tickets are sold. They have also demanded to know where the money is going.

Under present guidelines, APIs can cover public concerns, health, welfare, safety, government policies or 'operational objectives'.

A manager for some of the local artists performing at Harbour Fest said the concert was not completely commercial because his artists were not being paid full price.