The analogue signal is expected to be switched off in 2012

The government should help low income and special needs groups, according to the Consumer Expert Group, made up of charities and consumer organisations.

The government wants to turn off the analogue signal - which is used for conventional TV broadcasts - by 2012.

More information should be available about the switch, the group added.

The Consumer Expert Group was appointed by the Department for Culture, Media and Sport to offer independent advice on the future of digital TV.

In its report, it said a major concern was some people felt left behind in the digital race because they could not receive digital television in their areas.

Viewers can be assured that their interests, particularly those of the most vulnerable, will be at the heart of every decision Andrew McIntosh Broadcasting minister

The government says this will not be a problem once the analogue signal is turned off because that will free up space to increase digital terrestrial television broadcasts.

The group also wants a formal consultation exercise about the timetable and process about the switch-off.

And its report says 70% of households should have digital televisions as their main TV set before switch-off is announced.

Broadcasting minister Andrew McIntosh said the UK was already a world leader in digital TV, with 55% of the population already signed up.

He said the Consumer Expert Group was "knocking on an open door" with its recommendations.