Ministers will approve new BBC digital services allowing massive expansion of the home television network within weeks in a move certain to enrage commercial TV rivals.
Tessa Jowell, Secretary of State for Culture, Media and Sport, is expected to announce her decision at the Royal Television Conference in Cambridge on 13 September.
But the approvals will be granted only subject to super-strict regulations designed to safeguard both quality and public service principles. They are understood to go beyond what the BBC itself had proposed in detailed negotiations on the issue.
The announcement will give the go-ahead for the launch of four digital television services – BBC3 and 4, the beefed-up versions of the Choice and Knowledge channels, plus two children's services.
BBC3 is expected to offer new British comedy, drama and music programmes plus popular arts and education coverage. BBC4 will adopt a more intellectual tone.
Digital subscribers will be able to get the new channels through their existing packages without having to pay any extra. But more than £300m of licence-payers' money will be used to fund the expansion.
The Government hopes the existing analogue TV system will be switched off at some point between 2006 and 2010. By then, high street stores will be selling televisions built to receive digital without the need for set-top boxes.
But the digital approvals are opposed by commercial broadcasters, including Nickelodeon UK and Fox Kids Europe, who insist the new channels would merely duplicate the pay services they already offer. The BBC's controller of digital channels, Roly Keating, denies this.
A BBC source said yesterday: "We have obviously had lengthy negotiations and made some fairly strong commitments in terms of what we will do, not least that nothing will disappear from BBC1 and 2 onto the digital channels.
"We have an enormous commitment to original British production and absolutely upholding all the public service values of the BBC.
"One assumes the Secretary of State will hold us to all those commitments."
But Ms Jowell is keen to ensure early promises are not broken after digital approvals are given. The BBC will be told it must furnish more detail about its plans, particularly where "educational" television is concerned. Ministers will also seek assurances that the safeguards work long term. They do not want to see a situation in which well-loved or high-quality productions become available only on the digital stations.
Ms Jowell was due to announce her decision at the Edinburgh Television Festival this weekend but cancelled the engagement to comfort her son after the death of his former girlfriend Amelia Ward, killed by a rockfall on a school trip to South Africa a week ago, and to help her parents to prepare for the funeral.Reuse content