Ofsted has told ministers to cut the number of school improvement initiatives they devise and concentrate on schemes that really work.
The demand came in a report on the National Strategies, ironically released on the same day that Government announced another initiative - allowing schools to form chains.
Ofsted said the Department for Children, Schools and Families and National Strategies should: "Prioritise fewer school improvement initiatives and identify those that are demonstrably effective."
John Dunford, Association of School and College Leaders general secretary, said: "This reflects what we have been saying for several years and I look to Ofsted to provide more evidence on the success of Government initiatives so that the good ones can be expanded and the bad ones abandoned."
John Bangs, NUT head of education, said Ofsted should go further and tell Government to stop imposing initiatives on teachers. "An initiative will appear unwanted however many or however few they are if the Government says teachers have got to do them," he said.
The DCSF has made efforts to cut initiatives in the past, through ideas such as its Implementation Review Unit, designed to limit the burden placed on schools.
But Dr Dunford said: "The political tendency to meddle rather than build on strong existing foundations has blown the system hither and thither."
The report found the #163;4.5 billion National Strategies, designed to improve literacy and numeracy in schools and due to be disbanded next year, had boosted learning but suffered because of initiative "overload".
Ofsted's director of education and care, Patrick Leeson, suggested the Government concentrate on initiatives covering the core skills of maths, English, science and ICT.
A DCSF spokesman said: "Far from overburdening schools, the materials developed by the National Strategies have made a positive impact on the quality of teaching and learning in schools on raising standards overall and on narrowing gaps for vulnerable groups of pupils."