The company says it is too early to predict the effect that the UK's decision to leave the EU will have on its business
Marks and Spencer's latest financial report shows that its clothing sales fell by 8.9% in the first quarter - the company cited a "weak market" and fewer one-off hits.
Like-for-like food sales were also down by 0.9% - it past quarters when other areas of the business have lagged, food sales have held up and grown. The company said that its food division "continues to strongly outperform a deflationary market."
In May the group's new chief executive, Steve Rowe put a recovery in fashion and homeware sales at the centre of its growth plans.
The British firm says that consumer confidence softened in the lead-up to the UK's EU membership referendum on June 23rd. It added that it believes that it is too early to offer comment on the full impact of the vote to leave the Union.
After the results were published M&S shares fell by 1.2% - on top of a 29% fall during the quarter.
M&S added that it has expected a fall in total sales as it moved its summer sale back by two weeks, and offered fewer promotions - it believes that this made up 5% of the like-for-like sales fall.
Mr Rowe said that he is "confident that our strategic priorities and the actions we are taking remain the right ones to deliver results for our customers and our business."