Public support for national identity cards has dropped sharply in the past two years, despite the enthusiastic support of David Blunkett, the Home Secretary, for their introduction.

Opponents of ID cards, who include several cabinet ministers, will seize on the findings released today in a survey by Mori as proof that there is little popular support for the move.

In a survey coinciding with the Government's recent announcement that it was pressing ahead with the plans, 19 per cent of people chose ID cards when they were asked to name the best ways to cut crime. When they were asked the same question two years ago, 29 per cent selected ID cards.

The poll was carried out for the Rethinking Crime and Punishment think-tank.

Rob Allen, its director, said: "While the public wants more police on the beat, they are increasingly sceptical about the value of a national ID card in helping to reduce crime. They prefer policies which tackle the causes of crime ... rather than relying on enforcement. There is little appetite for more prisons."