Analogue TV signals will start to be switched off in two years' time, but a third of UK TV viewers are still unaware of the switchover.

A survey by Digital UK found that awareness has grown by 13 per cent since the launch of the Digit Al campaign, voiced by Little Britain star Matt Lucas.

But that still leaves one-third of people who have not heard about the digital switchover. 

Perhaps surprisingly, awareness is highest among the 65-74 age group, and lowest among 16-24-year-olds, fewer than half of whom know about the switchover.

The region with the greatest awareness is Border TV, where the switchover is due to begin. Analogue Border TV signals will be switched off in 2008.

Awareness is lowest in London, where only 59 per cent said that they know about the switchover. 

Digital UK polled 2,500 consumers for its first 'switchover tracking survey', which was conducted in association with broadcasting watchdog Ofcom. 

"These results are encouraging and demonstrate that the message about switchover is getting through, particularly to older viewers," said Ford Ennals, chief executive at Digital UK.

"We still have a lot of work to do in order to ensure everyone knows about switchover and understands what they need to do to prepare. This includes knowing that all televisions need to be able to receive a digital signal."