The Digital Radio Working Group (DRWG) has called for a long-term plan to move all radio services to digital.

The DRWG was established by the Department for Culture, Media and Sport last November to look into the future of digital radio. Representatives from the BBC, commercial radio and media regulator Ofcom participate in the working group.

In its interim report, the group recommends a medium-term plan to "migrate" all national, regional and large local stations to Digital Audio Broadcasting (DAB), with FM to be used by small local and community radio stations. This would begin in 2012 and involve switching to digital on a region-by-region basis to allow the radio spectrum to be reorganized smoothly.

The taskforce states that government should set out the conditions which must be met before this change could be achieved. The interim report identified gaps in coverage and signal strength as one of the potential barriers to take up from listeners.

However, it has not recommended a date for the nationwide switchover to digital radio, preferring a timetable for the migration of stations to be set out dependent on progess against the agreed criteria. The initial assessment is that this migration could be completed by 2020.

"At the end of May this year, sales of DAB sets exceeded seven million," says DRWG chairman Barry Cox in a statement. "We believe radio must have a digital future and that this will benefit both listeners and industry. Audiences will be able to enjoy increased functionality and more choice of channels, while the industry will no longer have to sustain the increased transmission costs of broadcasting on multiple platforms."

The DRWG will produce its final report by the end of the year.