Grade moved from the BBC to ITV in November

Airspace freed up from 2012's digital switchover could be used to bring HDTV to Freeview but Ofcom has proposed to sell it to the highest bidder.

In a speech to campaign group Voice of the Viewer and Listener, Mr Grade said bidding in an open market could create an "HD divide" between viewers.

But Ofcom argues it cannot specify what spectrum - or airspace - is used for.

Mr Grade's plea echoes that of members of the HDforAll campaign, which includes industry heavyweights such as the BBC, ITV, Channel 4, Sony, Samsung and the Dixons retail group.

They want part of the spectrum ringfenced for Freeview, saying Ofcom's proposed auction process means potential HD airspace could be sold off to the highest bidder, like mobile phone companies.

High-definition TV sets offer superior pictures and sound quality

They believe this will leave Freeview viewers with no access to the technology.

Mr Grade said Ofcom's approach could mean consumers would be left disappointed.

"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 public service broadcasting channels," he said.

"Indeed that is precisely what digital switchover seeks to achieve. Closing the door to HD on Freeview would undermine that principle," he added.

He went on to describe the situation as "an own goal".

Ofcom has said its hands are tied under the Communications Act and Mr Grade urged the government to intervene.

More airspace will be available after switchover because digital broadcasting is roughly six times more efficient than analogue.

Viewers of paid-for satellite and cable services already have access to HDTV - provided users have the proper equipment - but Freeview viewers require more bandwidth.