Within the UK it is illegal to use staff search unless you are listed on the paperwork as operating or supernumerary crew, indeed at LHR if caught you will lose your airside pass.
Well that's rubbish, unless you're telling me that none of the dispatchers, caterers, base managers etc are using staff search.
If the excuse by the cheap suits at DfT were to do with security, I might have limited sympathy. But tax? FFS! Collect it properly! Some of these people need to be kicked, literally kicked out of their endless flipping meetings and dragged, by the ear, over to where the professionals are trying to get the flipping job done.