British TV viewers face a hi-def divide unless Ofcom guarantees spectrum for Freeview HD, warns ITV chairman Michael Grade.

Grade said Ofcom's plan to auction off the former analogue switchoff was untenable and would "undermine the principle of equality at the moment we finally achieve digital equality."

"We've seen off the digital divide, only to see a high-definition divide. What an own goal," added Mr Grade, speaking to the Voice of the Listener and Viewer spring conference.

He argued that it was in the public interest to set aside some spectrum at a price that broadcasters could afford, to prevent Sky building a monopoly on high definition.

And he pointed out that Secretary of State Tessa Jowell could determine an allocation of spectrum, even if Ofcom's guidelines direct it to propose an open auction.

"Research shows there is strong and growing demand for HD and expectation among consumers that HD will be available on Freeview and we’ve seen in the papers today that Freeview has overtaken Sky as the UK’s first choice for digital TV," he added. "But Ofcom’s approach could mean that they will all be disappointed.

"Certainly the public service broadcasters would not be able to offer high definition television services on Freeview on this approach.  There just isn’t the capacity without additional spectrum – unless we closed down many existing services."And bidding in the open market for spectrum for free to air HD services on DTT simply does not make financial sense – regardless of the public value that would be delivered.

"There’s a real  risk that the UK – historically the envy of the world in this area – starts to slips behind the rest of the international pack in terms of the technical quality of its broadcasting.

"Most worrying of all is the public interest impact such a decision would have. We have a long and most honourable tradition in the UK of ensuring that everyone has access to the same quality of broadcasting and to the main PSB channels. Indeed that is precisely what digital switchover seeks to achieve.

"Closing the door to HD on Freeview would undermine that principle at precisely the point we finally achieve universality for digital television. We will have seen off the “digital divide” only to create an “HD divide” with high definition open only to those willing – and able - to pay. What an own goal."