The company said underlying sales growth for the July to September period came in at 0.6% compared with the same period last year.

Clothing sales, which account for about half the firm's turnover, were up by just 0.9%, hampered by hot summer weather.

But M&S said the impact of the heatwave had been partly offset by an increase in full-price sales, with 10% less clothing stock going into the summer sale than last year.

"The continuation of the hot summer weather did not help our clothing performance in September, but overall we have held our market share for the half-year," said M&S chief executive Roger Holmes.

The company added that overall sales in its newly revamped home furnishings division fell by 1.7%, pressured by a round of promotional activity.

In the City, M&S shares were down 2.5% at 307.75p in early trade, reflecting worries that the firm's recovery, which got under way two years ago after an earlier steep sales slump, may be faltering.