Anyone surprised at the news of Marks & Spencer’s sales slump should take a trip to Turnpike Lane in North London. There, with its sickly green signage and sad shop front, and surrounded by shops doing the same thing but cheaper, M&S Tottenham is visibly flailing.

Inside, between artfully bundled asparagus and £7 punnets of strawberries, the aisles were practically empty yesterday.

“I come here because the aisles are big and empty enough for my chair,” said Anthony Clements, 87, as he manoeuvred his electric buggy around the wine display. “And also, I hate all that two-for-one nonsense they do everywhere else these days.”

Unfortunately for M&S, it appears that Mr Clements is in a minority of one. A few doors down, staff at Sainsbury’s and Tesco could not keep the shelves stocked fast enough.

“Half price, two-for-one, buy-one-get-one-free special offers are selling faster and faster,” one Sainsbury’s shelf-stacker said.

Dom Tyerman, 28, left the shop with two carrier bags straining. “M&S is just not at all fashionable with my age group,” he said. “And it’s got a reputation for being expensive.

“When people see prices going up, they instinctively cut off what they see as the top band of shops from their shopping habits.”

Even M&S’s most devoted customers are deserting it. Catherine Rostel, 48, is the shop’s self-proclaimed biggest fan.

“I just love it,” said Mrs Rostel, who has shopped at M&S for 20 years. “I love their food and their clothes. I trust Marks & Spencer 100 per cent.”

But Mrs Rostel’s weekly food bill for her family of five is reaching worrying heights. “I’m spending £260 a week here,” she admitted.

“I just popped in now to buy some bits and pieces for packed lunches and when I looked at the receipt I got the biggest shock - £27.95. I didn’t even buy anything proper.”

She opened her bag to reveal packets of fruit and a few sandwiches. The sandwiches cost £3.50 each - malted wholegrain bread with luxurious fillings. “I think I’m going to start shopping at Aldi,” she said.

Mrs Rostel would not be the first. One mile down the road, the German discount supermarket was doing a roaring trade.

Like Mrs Rostel, Anita Leslie, 36, is a long-time M&S devotee. But yesterday, she was at Aldi, looking uncomfortable among the cardboard boxes and obscure brands. In her trolley were pineapples for 49p, punnets of soft fruit for 50p, packs of chicken breasts and salmon for £3, and a box of 15 frozen Yorkshire puddings for 55p.

“It’s definitely a different kind of shopping experience from M&S,” she said. “But I think it’s worth it. It would be nice to be able to buy top-quality, organic stuff every week . . . but I’d rather save myself 50 quid.”

The Aldi website, she said, had a calculator that could work out how much money one would save by shopping there. Assuming she shopped at Aldi for the next 40 years, Mrs Leslie’s savings came to £88,335. “That’s a lot of money,” she said excitedly. “They have a customer for life in me now.”

Saving money, it would seem, has become big business for Aldi.

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