The Welsh Assembly Government has told members that they must be more conscientious when it comes to refuelling their hire cars before returning them to dealers. The announcement comes after it was revealed that Welsh civil servants ran up a bill of £23,000 last year through service charges because they did not fill up their tanks.

The refuelling charges are up by £2,000 on last year and more than twice what they were in 2004. Jenny Randerson, a Welsh Liberal Democrats transport spokesperson, said it was shocking that at a time when the government was trying to save every penny possible; civil servants are wasting money by not bothering to refill their tanks.

Mrs Randerson added that anyone who has ever rented a hire vehicle will know how excessive the maintenance charges for things like topping up fuel can be. In June, the Lib Dems showed how over the last five years the Welsh Government had managed to rack up an astonishing £5 million in car rental bills.

According to the Lib Dems it was the pressure they put on the government which forced it to cut car hire expenditure from 2008′s figure of £1.04 million to £653,963 in 2009.

Mrs Randerson claims that if the government had not been forced to cut costs there is no telling how much its car hire bill would currently be. A spokesman for the Assembly Government said that a reduction in rental bills has been part of a long term strategy to drive down costs and was implemented well before the issue was made public.