Ofcom and the BBC Trust are planning a major upgrade of the digital terrestrial television (DTT) platform, which will see the launch of up to four new HD channels before digital switchover in 2012.
The first three will be made available as switchover takes place in the Granada region, and will follow elsewhere from 2009.
One of the channels will be reserved for the BBC. The others will be subject to a competitive bidding process open to commercial public service broadcasters including including ITV, Channel 4, Five and Welsh-language channel S4C.
It will be a 'beauty contest' - based on which broadcaster can make the best case for using the spectrum - and not a financial auction.
In order to add HD capacity to Freeview the current channel line-up will be re-organised and one multiplex upgraded with new compression standards, MPEG4 and DVB-T2. This will create room for a total of three HD channels by switchover with a fourth shortly after that.
The move follows an attempt last November by all the major terrestrial broadcasters to lead the roll out of HD services on Freeview.
Ofcom criticised the approach however, saying an industry-led initiative "would not allow for an open and transparent process of allocating what is valuable capacity on a public service multiplex".
Ofcom chief executive Ed Richards said today: “This is a once in a lifetime opportunity to upgrade digital terrestrial television.
“It offers benefits for broadcasters - who will be able to launch new services without using any new spectrum - and viewers - who will have access to new channels and services on free to air.”
BBC Trust chairman Sir Michael Lyons added: "We know from previous consultations that there is much support amongst the public for high definition services.”
The Digital Television Group has criticsed the used of MPEG4 and DVB-T2 saying that sufficent amounts of consumer equipment capable of dealing with those standards won't be ready in time.