A supermarket has blocked drivers from using a public parking area installed to improve safety and cut congestion at a neighbourhood shopping centre, flying in the face of a traffic order.

A much-needed lay-bay at The Glebe shops in Stevenage has been made unusable by Tesco because contractors employed by the supermarket chain have painted double yellow lines on it.

Drivers have been forced to avoid parking in the bay on Mobbsbury Way, Stevenage - opened three weeks ago to cut traffic chaos in the area, despite a ruling by Herts County Council that it can be used for loading only between 7am to 11am six days a week, and for any other reason at other times.

The lay-by was installed by the supermarket giant to solve the problem of lorries blocking half the road when delivering stock to the Tesco Express store, opened at The Glebe in January.

Workers added the yellow lines last week - despite a sign showing the parking conditions.

Robin Parker, county councillor for the Chells area, who petitioned for the lay-by, said the lines had rendered it useless.

“It is obviously a nonsense at the moment,” he said. “The double yellow lines completely contradict the sign and traffic order, since they prohibit waiting at any time.”

Cllr Parker was assured by the traffic authority, Herts Highways that the error will be corrected, “in that the double yellow lines will be removed as soon as possible.

“I wish to reassure residents that the yellow lines are not meant to be there and that vehicles can park in the lay-by.

“This should prevent lorries, particularly those now supplying the new Tesco store from blocking half of Mobbsbury Way at a busy and hazardous location,” he added.

A Tesco spokesman blamed Herts County Council for the blunder.

“We painted double yellow lines in the bay as they were included in the original plans at the time the site was approved. However, the council has since amended that order to allow parking during specified times, and we will alter the line markings accordingly.”