Ofcom is warning viewers could suffer temporary degradation or even total loss of TV services during the national switchover to digital broadcast.

As analogue signals are turned off and people around the UK switch to digital, the regulatory body said some antennas will need to be removed while new digital replacements are built. This, it said, “may affect the coverage of existing digital terrestrial television (DTT) and analogue services”.

In a review of its draft Code of Practice, which sets out to ensure the preparation to switchover to digital starting next year runs as smoothly as possible, Ofcom warned:

“It is likely that due to the extensive nature of the work being carried out and the complex planning relationship... some viewers will suffer a degradation in the quality of their current services or, in exceptional cases, the total loss of the current service."

Although Ofcom is trying to minimise disruptions, Uswitch believes people are being left out in the cold when it comes to communicating the risks.

“Although we welcome the move made by Ofcom and see it as a way to curb the disruption to existing digital services, not enough is being done to advise people about the potential loss,” said Steve Weller, head of communications at Uswitch.

“People need to know what is going to happen to them when it comes to the switchover so they can begin to prepare in advance.”

In a further twist, people have also been warned they may have to shell out to ensure they have digital coverage in cases of such disruption.

Ofcom's code suggests those disrupted by services for up to two weeks must be offered an additional service that does not require DTT - such as Sky - paid for by the service provider.

But, it adds: “It is expected that the viewers themselves will have to cover the normal costs of the necessary work that may be required to enable such a transition, including the reorientation of their antenna to a new transmitter.”

This could cost more than it would for a digital box. Therefore in order to minimise these costs, Weller advises consumers to act as soon as possible. He said: “There are some excellent deals at the moment, which will ensure consumers get better quality and more programme choice at better cost."

Analogue TV signals will be turned off region by region, starting with the Border TV region in 2008 and ending with London and Northern Ireland in 2012.

People and other interested parties have until 6 March 2007 to comment on the draft code of practice. Broadcasters will be required to comply with the code once it has been finalised.

DigitalUK, the company responsible for the switch, was unable to comment due to its ongoing discussions with Ofcom.