The government's long-awaited communications bill, set for publication in May, will continue to prevent media organisations with over 20 per cent of the national newspaper market from buying more than a 20 per cent share in ITV, Channel 4, Channel 5 or a national radio channel.

New cross-media ownership rules will allow ownership of up to 20 per cent in local radio, but will be regarded as a setback to Rupert Murdoch's ambitions for expansion.