UK commercial director Gary Killeen explained: 'If you look at a mainstream fleet car, such as a Ford Mondeo with a 70 litre tank, then with petrol and diesel prices around 140 pence per litre, we are now just a couple of pounds away from the £100 fill up.

'This could be an important psychological barrier. Some cars on fleets, such as 4x4s and executive models, have long since crossed the £100 fill up threshold but we will soon be reaching a point where most of the vehicles on a given fleet at any grade will hit three figures at the pumps.'

Killeen said that the shock of the £100 fill-up could prompt fleets to take action on fuel spending but that historical precedents were not encouraging.

He explained: 'Fuel prices rise so fast that we cross these psychological barriers all the time – the £1 litre, the £5 gallon, the £6 gallon. You would imagine that they would create a real impetus among fleet managers but many see that this is an area which they cannot influence directly.

'However, the opposite is true. While petrol and diesel prices are likely to continue rising well above the rate of inflation, there is much that can be done to minimise the effect of them, from better fuel buying, acquiring more efficient vehicles, educating drivers to change their driving style to minimising fraud.'