A power cut knocked out supplies to a Stevenage neighbourhood last night leaving hundreds of homes without electricity, shutting down traffic lights and putting a supermarket on back up supply.

An electrical fault in an underground high voltage cable at 6.10pm stopped supply to 603 customers in the Coreys Mill area.

Sainsbury’s was left with emergency lighting and blinds pulled down on aisles to keep food cold, while the supermarket petrol station was forced to shut.

Traffic lights on the Hitchin Road also went out, leaving motorists cagily crossing junctions.

Engineers restored supply to 99 customers within four minutes while 503 had normal service again by 7.20pm, UK Power Networks said. Full service was restored by 8pm.

The company apologised for the inconvenience.