In a further attempt to draft support for the beleaguered identity cards proposals, the Prime Minister has sent an email response to the almost 28,000 people who signed a recent online petition against the scheme.

The petition, which closed on 15 February and attracted thousands of supporters, purported that the introduction of ID cards would not prevent terrorism or crime, but would instead be a form of indirect tax.

According to the email from Tony Blair, the petition attracted one of the largest responses since the service was set up. “So I thought I would reply personally to those who signed up, to explain why the Government believes National ID cards, and the National Identity Register needed to make them effective, will help make Britain a safer place,” he added.

Blair used the email to reiterate the role ID cards and biometric technology would play in securing national borders, countering fraud, and tackling international crime and terrorism. The Prime Minister also attempted to play down concerns about the controversial National Identity Register, which he argued “will contain less information on individuals than the data collected by the average store card”.

Benefits such as speeding up checks on those wanting to work with children; potentially helping to crack around 900,000 unsolved crimes; and preventing illegal immigration were also outlined.

On the issue of the cost of the scheme, the Prime Minister argued that some estimates were deliberately exaggerated. According to government figures, 70 percent of the cost would be accounted for by biometric passports, which Blair claimed would become obligatory anyway for any foreign travel, with the additional ID cards element adding £30.

Tony Blair may have a bigger job on his hands trying to convince the UK public about the benefits of the proposed road pricing scheme, however. A similar online petition set up to urge the government to scrap the road charging plans had attracted more than 1.6m signatures ahead of the 20 February deadline.