ISBA and the IPA have stepped up calls for a single regulatory body to govern UK television following the BBC's controversial decision to go ahead with moving its 9pm news to 10pm.
The new bulletin will clash with ITV's reinstated News at Ten and advertisers see it as evidence that the BBC is flouting its remit as a public service broadcaster.
John Hooper, the director-general of ISBA, said: 'The evident lack of a single authority for the overall UK broadcast ecology is why there must be a single regulator that oversees the BBC and the commercial sector.'
Jim Marshall, the chairman of the Institute of Practitioners in Advertising, said the advertising body would step up its efforts in lobbying the Government to appoint a single broadcasting regulatory body as it mulls over the recent submissions for the white paper on broadcasting.
Marshall said: 'This move is a very obvious statement of intent that the BBC is going to go after ITV's audiences. There is no doubt that the BBC acts like a competitive commercial channel, even though it is an organisation that has a charter to extend viewers' choice.'
The BBC, which is now trying to poach ITV's Trevor McDonald, will broadcast its main news bulletin at 10pm from 16 October. Advertisers are concerned this will increase ITV inflation by cutting the channel's audiences.
However, John Hardie, ITV's marketing director, hit back: 'Clearly we will have more commercial competition at 9pm and that is our stronghold. We will take this seriously, but to start worrying about significant TV inflation is a premature reaction,' he said.