An “unexpected uplift” in Mini orders for May means that employees at BMW’s Cowley plant are being asked to work an extra three hours per week next month, lifting their weekly working hours from 37 to 40.

The latest figures for March show the Oxford-built Mini's worldwide sales were down 18.5 per cent in March at 21,888 cars, compared to 26,841 in the same month in 2008. Annual Mini sales were down 24.9 per cent at 43,592, compared to 58,054 in the first quarter last year.

The Mini’s parent company, BMW Group, saw a drop of 17.2 per cent in March to 126,375. The annual sales decline was 21.2 per cent.