Two points:
With regard to the "bringing to book" of the guilty party who wrote said letter - as has already been suggested, this is probably some clerk on £12,000 per annum, sending out a standard letter. In fact, I wouldn't be surprised if it was automatically produced by the payroll / HR system. I happen to HATE standard letters being issued for ANY correspondence, but then again, you can't always be too sure that your clerk can string a sentence together. That aside, the "bringing to book" will be part of the MOD investigation as promised by Tony Blair. The particular individual will probably be given a Disciplinary / Capability interview, which is private. Internal systems will also be examined. But if you're looking for a scapegoat - don't. If this person loses their job over this, you get bet your boots he or she will win at an ET / EAT.
Secondly, with regard to civvy companies being prosecuted for failing to pay the correct (contractual) salary or increment, Flash-to-bang - the way they get around this is putting a clause into the Contract of Employment which basically boils down to "if we muck up your pay, we'll try to sort it out EVENTUALLY, whether it's overpayment or underpayment, and you agree to this". Withholding payment due to other reasons for deductions as opposed to just f-uck-ups are a different matter. By signing the contract the employee agrees. By refusing to sign the contract but continuing to work and be paid for it, can also be seen as accepting the contract.
Or so I understand. We'll probably get some legal bod on here who will rip that to shreds.
