According to the IPA's TV Trends report for the first quarter of 2006, which came out this week, digital TV now accounts for more than 30 per cent of TV viewing.
However, Jim Marshall, the chairman of Starcom and of the IPA's Media Futures Group, said the remaining 70 per cent represents a challenge for the Government.
He said:"I don't think the Government has done enough in terms of understanding and addressing the concerns of homes that haven't switched to digital."
Graeme Canter, a director of TV at MediaCom, agreed with Marshall that the Government is not doing enough. "Other than food and drink, if you take TV away from people in this country, it's the worst thing you can do," he said. "These things don't happen overnight."
The phasing out of analogue TV broadcasting in the UK will begin in 2008.
Digital UK, the marketing body charged with pushing digital television, launched an ad drive earlier this year.