Nicola Sturgeon’s flagship policy of doubling “free” childcare for three and four-year-olds has been dealt a major blow after a “bombshell” report found fewer than one in three private nurseries are likely to offer the extra hours.

The National Day Nurseries Association said the sector was at crisis point due to a lack of funding and the plan to expand paid-for nursery places was now “at risk”.

Its annual survey found confidence among private nursery providers at an all time low, with 30 per cent saying they were likely to meet the target, compared to more than 50 per cent last year.

The Scottish Government has pledged to increase paid-for nursery places from the current 600 hours to 1,140 hours for three and four-year-olds, and eligible two-year-olds, by August 2020 - the equivalent of about 30 hours a week in term time.

But the association said funding shortfalls had widened and many owners feared they would be forced to close.

It said more funding was needed now and warned that the requirement to pay staff the “real living wage” would cripple nurseries unless extra cash was made available.