NATIONAL Grid says a massive York power cut was caused by a problem at a substation near the city.

A spokeswoman said this morning's outage had been traced to a fault on an electricity transformer at the substation.

"We’ll now be investigating to find out exactly how and why the fault occurred," she said.

Power was lost at just after 9am to 26,943 properties across York, including city centre businesses, as well as traffic lights.

The spokeswoman said more than 21,000 properties had their electricity supplies restored within nine minutes, and the remaining properties by 9.45 am.

A business conference at the City Screen cinema in Coney Street, attended by about 200 people, went ahead despite the cut, but moved into the cafe without the use of microphones, before power was restored at 9.45am.

Hanus Wolf, owner of Burgin's perfumery in Coney Street, said its power went off just after 9am and was restored at 9.45 am.

He said he had to turn away about £150 worth of trade because customers wanted to pay by credit cards and the machines were not working.

"It seems to happen every winter," he said. "I don't know whether or not it's because of a surge in demand but it always seems to happen at this time of year."

Meanwhile, in Bishopthorpe Road, shops on one side of the street were blacked out while ones on the other side kept their power supplies.