The latest batch of figures highlights the strain on household budgets labouring under heavier mortgage payments and sharply rising energy and food costs.

It adds to clear evidence of changing spending habits in recent weeks as consumers negotiate the worsening economy. Sales at Aldi, the "pile it high, sell it cheap" grocer, jumped almost 20% in the 12 weeks to mid-August, compared with the same period a year earlier, while sales at rival Lidl were up 12.3%.

Analysts have begun to talk about the "Aldi effect" as shorthand for discount and low budget retailers that are benefiting from the credit crunch.