I am PAYE and paid an hourly rate, if I drive a van from home to work I get paid from 7.30 to 4.00 but we are allowed to leave at 3.30 and paid 7 1/2 hours but if I drive a 7.5 tonne lorry and leave yard at 6.15 and return 4.15 should I get paid 10 hours as time on duty or 7 1/2 hours as if driving van.