Warm weather has boosted sales of summer fashions and food at Britain’s biggest clothing retailer Marks and Spencer.The group reported its smallest quarterly sales decline in almost two years. M&S, which sells clothes, household goods and food at more than 600 UK stores and about 285 abroad, says it remains cautious despite the positive signs on consumer sentiment. Britain’s retailers are battling the deepest recession in decades. Industry sales are falling and a raft of companies in the sector have posted slumps in annual profits. M&S says sales at UK stores which have been open more than a year fell 1.4 per cent in the 13 weeks to June 27 after a fourth quarter drop of 4.2 per cent. It may have been the seventh quarterly fall in a row but it is the best performance since the second quarter of the 2007-2008 financial year.