Data loss statement urged

Shadow home secretary David Davis said that Mr Darling must explain to MPs at what level within the HMRC management structure the bulk despatch of personal data was sanctioned.

And he challenged the Chancellor's claim that the mailing was the responsibility of a single junior member of staff acting in breach of HMRC procedures.

Mr Davis told BBC1's Andrew Marr Show: "We are demanding that Alistair Darling comes back to the House because we don't know if we have been told the truth, but we certainly haven't been told the whole truth about this episode."

MPs were no longer sure "whether this was a civil service failure, let alone a civil service failure by a lone member of staff" rather than the result of faults in the system imposed by ministers, said Mr Davis.

Mr Brown was responsible not only for merging the Inland Revenue and HM Customs and Excise, but also for transferring responsibility for dispensing child benefit to the agency, making its work significantly more complex, he said.

And he added: "I think accusing a junior member of staff of being responsible for this whole problem is at best ignominious and at worst dishonourable."

Mr Davis said he believed the loss of HMRC data had brought home to the public the dangers of introducing ID cards and creating a National Identity Register containing biometric details, such as fingerprints, of every British resident.

"If you create a National Identity Register, you might as well take a CD and put it in an envelope and send it to Osama bin Laden," said Mr Davis.

"This could be a very serious issue at the next election and that is what's worrying Labour MPs. They are thinking `Am I going to have to defend this £20 billion white elephant that is going to put everybody's security at risk at the next election? What's that going to do for my marginal seat?' That's going to be the driver to stop what I think is, frankly, a mad idea."