The roll out of national biometric identity cards may be delayed for at least a further two years, according to leaked Home Office documents.

The papers, obtained by the Conservatives, show that though compulsory cards will be issued to foreign visitors this year, UK citizens will only received one when applying for passports from 2012, instead of the 2010 target date set two years ago.

The changes also raise questions about government plans to make the cards compulsory, after seeking parliamentary approval, from 2015.

The disclosure of the new "delivery strategy" adds to the embarrassment of Prime Minister Gordon Brown over government data loss scandals culminating in the stolen Royal Navy lap top containing personal data on 600,000 individuals.

The scheme was dealt a considerable blow when discs containing data on benefit claimants went missing and a series of other data scandals emerged.

The leaked documents appear to suggest teachers and others in "trusted" professions would start to get cards ID cards selectively next year.

Shadow home secretary David Davies said the ID card scheme "is in the intensive care ward".

His claims appeared to be backed up by allegations the Treasury is sitting on a review of the scheme completed by former senior banker Sir James Crosby which were due to be published in the Autumn.