Home secretary Jacqui Smith has insisted biometrics taken from people in high-street businesses will be secure.

While anti-ID campaigners have said it will be almost impossible to lock fingerprints to biographical details in a secure manner if those biometrics are taken in a high-street business, Smith said on Thursday that the process would be secure.

"It is clearly important, and part of the work we are doing and the plans we have in place, to ensure the secure, controlled transfer of any biometrics," Smith told ZDNet UK at a press event. "I believe it is technically possible to do that. I don't see the challenge is greater because more people are accredited to do it."

Smith added that accredited businesses would have a strong competitive reason to ensure that the biometric transfers they perform are secure, as failure to do so would have an impact on their reputation. However, so far the Home Office has given no precise information as to how fingerprints would be linked to biographical data, or any details about how the National Identity Scheme would be implemented.

High-street enrolment-centre service providers would be accredited by the Identity and Passport Service, said Smith, who added that "enrolment should be able to take place in the post office and shopping centre".

Smith criticised both the Conservatives and the Liberal Democrats for saying they would scrap the scheme.

"I can't answer whether the Tories would cancel the ID scheme," she said. "[If they do] they will have to answer how they will fill the black hole not only left by ID cards but biometric passports. They would have to answer why they have taken away security and convenience from the British people."

Conservative shadow home secretary Dominic Grieve told ZDNet UK in an emailed statement that his party would discontinue the scheme, a move he said would benefit security.

"We would scrap this expensive white elephant and use the savings to do things that would actually improve our security," Grieve said. "The home secretary should stop kidding herself, admit this project is dead and devote her energies to carrying out her primary responsibility, which is ensuring the safety of the citizens of this country."

Anti-ID card campaigner Phil Booth said that far from increasing security, ID cards would be a risk.

"They are not introducing security and convenience, they are doing exactly the opposite," Booth told ZDNet UK. "Enrolment in the high street will introduce security holes a mile wide. People will link biometric details to false biographical details, while the system will be plagued by systems errors."

The campaigner added that biometric passports, drivers' licences and other forms of identification would not be affected if ID cards were scrapped.

"This has nothing to do with passports, driving licences, or anything else," Booth said. "Get rid of the ID cards scheme and all the issues go away. There will be no 'black hole' left anywhere."