Go cheaper
It is like in most Countries: The collector has to use his money wise and for the purpose he claimed reason if you have a company or a similar enterprise.
As soon as you are the Taxcollector you can use the money imposed from Air Tax or Petrol Tax to seal any other overdue expenses as you like. People call that missuse, as a government you call that what ?
Another fair share on the downturn of Transit Passengers at LHR is the close to disgusting way most of our Customers get "handeld" from the BAA Security. Also something to think about. I had several occassions when I talked with C-Class Travelers who under no circumstances want to transit in London anymore. Something to think about, but the people concerned will not do it, I am sure. They use Taxpayers money as it belongs to them.