Gordon Campbell has a technological answer to the problem of unauthorised Ministerial spending:
To prevent misuse of company cards in the private sector, US firms routinely use a service that Visa and some other card holders have offered for years – namely, Merchant Category Codes (or MCC).
These codes entail a four digit number that automatically refuses to accept certain categories of spending, or spending in certain locations.
This subject came up over dinner with one MP a few months ago and he suggested a simpler solution: that all Ministerial credit cards issued have a picture of Duncan Garner’s face printed on them. We agreed that would be a far more effective deterrent than any improvement in process or oversight committee.