Schools watchdog Ofsted has become unwieldy and must be split in two, MPs warned today.
The inspectorate has grown "too big" as it has taken on more responsibility and is no longer able to operate as efficiently as smaller organisations could, according to a report by the Commons education select committee.
Ofsted now has responsibility for inspecting children's services, including areas such as social care and adoption agencies, as well as schools.
In a report on the role and responsibility of Ofsted, the cross-party group of MPs concludes that splitting the inspectorate in two would boost confidence in inspections.
It calls for the creation of an Inspectorate for Education and a separate Inspectorate for Children's Care.
"We believe that having a single children's inspectorate has not worked well enough to merit its continuation," the report says.
It adds: "Ofsted has grown too big to discharge its functions as efficiently as smaller, more focussed and specialist organisations might."
The report also warns that too few inspectors have recent and relevant experiences of the type of institutions they inspect.
The committee concludes that the two new inspectorates should remain independent of Government, but calls for ministers to create two new positions - Chief Education Officer and Chief Children's Care Officer - to work alongside them.
The report adds that the new Education Inspectorate should make looking at the progress made by every pupil of every ability a priority, and these results should be given as much weight by the Government as other measures, such as the number of pupils getting five good GCSEs.
Graham Stuart, chairman of the committee, said: "Ofsted's reach is vast and its remit has grown substantially since its inception, but this has come at the expense of providing a more specialised service.
"We need a radical shift in how inspection operates in this country, with a more proportionate, specialist and focussed approach.
"Ofsted has, of course, made a great impact on the quality of provision across the country, but the evidence clearly shows that smaller, more focussed organisations could do even more so."
Ofsted chief inspector Christine Gilbert said: "The question of 'who inspects?' is much less important than the quality of inspection and the impact it has on raising standards and improving people's lives. Ofsted is proud of the work it's done across the whole of its remit since it took on its present brief in 2007.
"Any proposal for further reorganisation needs to be very carefully considered and is ultimately a matter for the Government. There are issues about additional costs and a risk of distraction from the core business - namely continuing to deliver high quality, rigorous inspection which helps to drive up standards for children and learners everywhere."
Brian Lightman, general secretary of the Association of School and College Leaders (ASCL) said: "Education and children's services have very different needs and priorities. Separating inspection of education and children's services into two divisions linked by good lines of communication is the right move and will help to ensure appropriate expertise in each area."
In response to the Education Select Committee's review into the role and importance of Ofsted, Barnardo's deputy chief executive Jane Stacey said, "Acknowledging development and looking at how far a child has come is crucial. The proposal for Ofsted to prioritise measuring pupil progress is one that complements Barnardo's ongoing commitment to improving the lives of the most disadvantaged and vulnerable children and young people.
"Barnardo's agrees that a structural re-design to clarify Ofsted's extensive remit would be a positive step forward. A rationalised Ofsted should continue to play a vital part in ensuring that accountability remains a leading priority within the education and children's care sectors, giving each the expert focus it deserves."
"However, Barnardo's will be looking for reassurance that any proposed division will not compromise multi-agency working and the shared responsibility of schools and other agencies for safeguarding and promoting the welfare of children.
"Inspectorates should be expected to work closely together to improve outcomes for children and dual-service settings such as nurseries and children's centres should not be left in limbo, unsure of whose watchful eye they fall under."