Plans for the introduction of identity cards in the UK have been thrown into confusion after leaked government memos cast doubt on the future of the project and two key backers pulled out.

BAE Systems and Accenture have both announced that they are pulling out of the plan, which could cost individuals up to £500 each.

"At this stage of the competition our assessment is that our bid would not contain every element necessary to deliver to the customer's requirement. We continue to monitor the programme with interest," BAE told Reuters.

Accenture gave no reason for its withdrawal but said that the company " remains committed to our work in UK government".

CSC, EDS, Fujitsu, IBM, Steria and Thales remain on the list of contractors, but the government will now have to run an additional round of supplier reviews to fill the gaps left by BAE and Accenture.

Meanwhile two memos leaked over the weekend have raised doubts over the entire project.

The first suggests that fingerprint data, a key plank of the security of the cards, may not now be included for cost reasons.

Dame Stella Rimington, former head of MI5, has already stated that the cards will be "absolutely useless" without fingerprint data.

The lack of fingerprint data also represents a further scaling down of the scheme, which was originally supposed to include iris scans and an interlinked national database.

The second memo, entitled Options Analysis, contradicts prime minister Gordon Brown's promise that the cards will be voluntary, as it outlines government plans to introduce step-by-step coercion for new documentation.

"Various forms of coercion, such as designation of the application process for identity documents issued by UK ministers (e.g. passports) are an option to stimulate applications in a manageable way," says the memo.

"There are advantages to designation of documents associated with particular target groups, e.g. young people who may be applying for their first driving licence."
If UK citizens still refuse to sign up to the scheme the memo allows for full enforcement of use, but states that "universal compulsion should not be used unless absolutely necessary".

The national ID card plan was the brainchild of Tony Blair but the law enacting them barely made it through the Commons and was repeatedly cut by the Lords.