Advice
Leopard Bloom has it right. Watch the AW web site. Flysmart, your not quite correct.
Owd Yella
You know who to call. You wont get tax free salary you either get the equivalent of UK tax and the company your thinking of regularise your salary - but you retain all the UK benefits. Or, you pay T+T taxes which looks good at 25% but you lose all your state stuff on return. Swings and roundabouts. The package has changed a lot since you spoke - if you who I think you are.