THE number of NHS patients waiting too long for non-­emergency treatment has doubled under David Cameron, the latest figures showed yesterday.

Patients waiting longer than 18-weeks for treatment increased from 20,662 in May 2010 to 39,466 in February, according to NHS England.

The overall target — to treat 90 per cent of patients within 18 weeks — was missed with 87 per cent seen on time, down from 92.9 per cent in May 2010.