Free parking at Morrisons and B&Q could come to an end after a council report found these car parks cost Sutton Council £200,000 a year in lost revenue.

In a major shake-up of town centre parking the council has written to the owners of free time-limited car parks to remind them of their legal duties.

"When these stores were granted permission there were restrictions built in to the 106 agreements ensuring that parking in the car parks was controlled by the stores and kept to customers only.

"This has not been the case with Morrisons, B&Q and to a lesser extent, Asda," a council report states.

The council has also held a separate meeting with the management of Morrisons.

But a spokeswoman for Morrisons denied parking was unregulated at the Sutton store.

"Morrisons Sutton has strict regulations in force on its car park, and while on the whole we depend on the honesty and goodwill of our customers to use it appropriately, the car park is fully patrolled and managed.

"Our regulations state customers must park in designated car parking spaces and that there is a maximum stay of two hours. Customers who exceed the two hour stay will be issued with a charge," she said.

A B&Q spokeswoman said efforts will be made to control parking.

"We are in the process of reviewing the car park management system at the store and will be applying parking restrictions as required to ensure that we provide sufficient parking at the store for B&Q customers," she said.

The council also plans to upgrade ticket machines in its car parks and replace staffed parking booths with centralised patrols. It may also put out to tender the refurbishment of Times Square car park which last year lost its "Secured Park Mark" award because of its condition.