The discounts were identical, but the response north and south of the Border was anything but.

As Marks & Spencer mounted its first “one-day spectacular” in four years, executives waited to see if a 20 per cent saving would get consumers to bite.

Reaction was muted in London, where customers are used to pre- Christmas discounting. Some even said they would return stock and quietly repurchase it at a lower price.

“It’s only 20 per cent,” shrugged Karen Bethell, outside a Central London M&S. “It’s just not a great deal. I try not to buy anything at full price now.”

Ahmed Ali, a 30-year-old lawyer, was taking back a full-price suit he had bought. “The sale is one of the reasons I’m taking it back. There’s going to be another sale before Christmas the way \ sales are tumbling.”

Only a few people were waiting at the flagship M&S store at Marble Arch store when it threw open its doors an hour early.

“It wasn’t busy at all,” said Kirsty Bowman, 25, as she departed with £65 of underwear. She arrived at 8.10am to beat crowds that never came.

But hundreds of miles away, Scots kept the 30 tills busy all day at one M&S branch in Aberdeen.

At the Argyle Street branch in Glasgow, Scotland’s biggest, customers waited for up to an hour to pay.

Helen Clark, 60, from Cambuslang, South Lanarkshire, spent about £110 on Christmas presents for her family and would not have contemplated shopping there without the 20 per cent saving.

“I was buying pyjamas for my daughters and I normally go to Primark,” she said. “The queues were dreadful, but if you want a bargain you have to suffer.”

Sir Stuart Rose, the M&S chief executive, deemed the sale a success, though the company does not release trading figures.

“It seems to have hit the spot,” he said. “It’s been an absolute riot.”