Marks & Spencer has fuelled fears of a deeper downturn on the high street by bringing forward its next trading statement by a month.

The department store chain is to unveil second-quarter sales figures on October 2, ahead of half-year results on November 4. It previously ditched quarterly reporting in 2006.

The change has worried some City analysts. Oriel Securities analyst Eithne O’Leary told The Daily Telegraph: “This confirms the suspicion that things are difficult. It is a necessary return to best practice given the pressures on the consumer and the wider economy.”

M&S and other more upmarket grocers have suffered from the growth in discount supermarkets over the past few months as consumers tighten their belts.

An M&S spokesman said: “In more uncertain economic times, we felt it was better not to have too protracted a period between trading statements.”