Cash-strapped Thames Valley Police is spending £77,655 on its new-look vehicles -- the equivalent of four new police constables on the beat.

But officials say the makeover from 'jam sandwiches' to 'Battenburg cakes' will be worthwhile and will recoup its cost.

The new livery was introduced last month at the instigation of the Association of Chief Police Officers.

The familiar white police vehicles with red stripes now have yellow and green squares down the side. The cost is £167 per vehicle.

Ian Godolphin, the force's fleet manager, said police vehicles averaged 36,000 miles a year in their normal economic life of two years and nine months.

He said; "There is scientific proof that the new markings are the most effective available.

"If they prevent just one accident involving a police vehicle per year -- average cost £3,000 -- they will recover their costs.

"Most importantly, the cost in human suffering of just one accident will have been prevented, and that is immeasurable."

New vehicles will be delivered in the new livery straight away, vehicles up to a year old will be repainted, and vehicles over a year will keep their existing livery until they are taken out of service.