Beware . This is a very dangerous situation.
I can only advise you from the South African perspective, but I should imagine the UK DCA would be similar.
DCA is very tough on any SMELL of money.
As a PPL you cannot even share the cost of a holiday jaunt among friends. Whoever hires the plane has to pay ALL THE COSTS, friends cannot even chip in for the fuel.
Any breach will mean no insuarance cover and posible loss of licence.