A woman waited two hours for an ambulance after a fall in the Sainsbury's store in Farnham Road, Slough left her unable to move and in agony as shoppers watched helplessly.

Slough man Paul Janik who was on the scene said: "Shoppers were visibly distressed at seeing the woman in agonising pain. But they were powerless to help her.

"Her leg was straight out in front and she could not move.

"She was reliant on the ambulance service and it let her down."

He said Sainsbury's staff tried to help by keeping customers away from the spot where the injured woman was and police also attended the scene.

Yesterday (Thursday) a South Central Ambulance Service NHS Foundation Trust (SCAS) spokesman confirmed that the call had come in at 7pm and that the ambulance had arrived at 9.7pm - two hours later.

The spokesman said the call had been classified as a Category 4, which requires attendance within three hours.

She said that nearly year ago the SCAS had moved to new national Ambulance Response Programme (ARP) targets which has changed the way that ambulance trusts across the UK need to respond.

She said: "This ensures that the most critically injured or ill patients receive the fastest response. The arrangements help SCAS respond more quickly to calls where a patient is suffering a life threatening illness or injury. The changes ensure a more efficient use of our available resources and provide greater flexibility for our dispatch teams so they send only the most appropriate resource to individual patients. This in turn should reduce the long waits for an ambulance that some patients may have experienced in the past."