The figures, based on 3,582 inspections between 1 April and 30 June 2013, reveal that three times the number of childminders were found to be inadequate year on year (6 per cent), and more than two times the number of nurseries (8 per cent).
There was also a rise in the number of nurseries graded satisfactory, from 16 per cent in 2012, under the old inspection framework, to 24 per cent this year.
All inspections from 1 September 2012 were conducted under the new framework.
In contrast, the percentage of nurseries judged as good fell from 67 per cent during 1 April to 30 June 2012 to 55 per cent the same time this year.
There was also a decrease of two percentage points, from 15 per cent to 13 per cent, in the number of nurseries found to be outstanding compared to last year.
The Ofsted statistics, ‘Early years and childcare registered providers and outcomes April-June 2013’, show that in total seven per cent of settings were inadequate, 24 per cent satisfactory, 59 per cent good and 9 per cent outstanding.
The Pre-School Learning Alliance and the National Day Nurseries Association have jointly criticised Ofsted's statistics for a 'lack of transparency'.
Neil Leitch, chief executive of the Pre-school Learning Alliance, said, 'For the third quarter in succession a headline reading of these statistics indicates that one in 12 providers are judged to be inadequate under the new inspection framework.
'Ofsted says that the lower ratings are due to the first year of the new framework concentrating on "weaker providers". But, as ever, the devil is in the detail. These statistics indicate the overall performance level but we do not know how many of these inadequate judgements are the result of complaint-initiated re-inspections, which have seen good or outstanding providers significantly downgraded. Nor do they provide any detail of how many indicative inspection outcomes were subsequently overturned by the Quality Assurance process.
'These statistics also provide no information about how many providers went from outstanding to satisfactory or satisfactory to good.
'Ofsted has said publicly that it makes no apology for promoting improvements in early years provision and that parents will be pleased to hear that its new, more rigorous inspection framework is helping to raise standards. However, should Ofsted continue on the path it has taken, the unintended consequence of its actions is likely to be that parents will find it harder in future to source childcare, and they will not thank Ofsted for this.'
Purnima Tanuku, chief executive of the National Day Nurseries Association, said, 'These statistics will sound alarm bells for the early years sector.
'We understand Ofsted inspects weaker nurseries as a matter of priority and these quarterly figures will reflect this but what we don’t know is how many of these inspections are not in that category but are complaint-driven. A complaint-driven inspection is a very different matter and we would like to see greater clarity on the movement of inspections and what is driving them.
'For a sector already concerned about Ofsted’s approach to inspections these figures are not going to offer any comfort. We cannot afford for this trend to continue with inadequate gradings and while we all want a robust system which ensures children are getting the best possible care, there must be confidence and consistency in the system.'