The firm which runs the country's only fee-paying motorway reported 66,295 vehicles travelling on it on 28 May.

Midlands Expressway Ltd (MEL) admitted although average daily use had risen by 39.8% since January, figures for all of May fell by 4% compared to April.

Friends of the Earth in the region said it showed the route was not a solution to the area's traffic problems.

Tom Fanning, managing director of MEL, said despite recording the highest day of traffic in May the additional public holidays had affected average daily traffic with numbers falling from 44,689 in April to 42,862 in May.

He said the number of vehicles using the M6 Toll on weekdays in May had also fallen compared to April.

But he said the average traffic numbers over the three days of the bank holidays showed that the route was proving popular for people travelling away for a long weekend.

'Bad news for environment'

And he predicted a busy summer for the 27-mile route, which opened last December, to connect Junction 11 of the M6 in Staffordshire with Junction 4 in Warwickshire.

But Friends of the Earth West Midlands co-ordinator, Chris Crean, said he was concerned at the drop in the amount of traffic from April to May.

"These are not the sort of figures that MEL talked about in the public inquiry when they boasted about an average daily figure of 75,000 vehicles per day.

"This piece of infrastructure is obviously not attracting the private motorists in the way MEL predicted, this is bad news for the West Midlands economy, transport and environment.

"We need this sort of investment to be focused on public transport provision for the people of the West Midlands.

"Not a motorway which destroys precious green belt and increases reliance on the private car."