Schools with satisfactory exam results will today be told they must do better.
Ministers will identify a number of "coasting schools" in England, where pupils are not fulfilling their potential and should be making more progress.
Schools secretary Ed Balls is set to outline a new policy later today to push such schools to improve their performance.
But teachers have warned that the government must avoid putting schools into "crude categories".
There was a backlash this year when the government announced a list of the worst-performing schools in the country, which came under their National Challenge initiative.
At that time, some of the schools listed in the scheme - which aims to improve schools where fewer than 30 per cent of pupils get five good GCSEs, including English and maths - said they were vilified for their inclusion.
Mr Balls will today say that local authorities have been asked to identify "coasting" secondary schools in their area, and invited to bid for a share of £40m in government funding to provide support to their chosen schools.
The schools will be encouraged to link up with others in their area to share best practice, and will be given access to additional resources to form trusts or federations if necessary.
There will be a focus on making learning more interesting and relevant to pupils, and teachers will be given extra training on tracking students' progress.
But Christine Blower, Acting General Secretary of the National Union of Teachers (NUT) said categorising schools was an unhelpful Government "fixation".
She said: "Each school is unique. Their definition into crude categories is a continuing obsession of the Government.
"I'd like to see Ed Balls go beyond criticism of schools by category and map out, in conjunction with the profession, a positive and pro-active way as to how the in-depth expertise of teachers and schools can be harnessed for their mutual benefit. Funding research into looking at ways to gain a greater insight into what actually makes schools work effectively would be a good step forward.
"I'd also like, once and for all, for Ed Balls to drop the idea of floor targets. They tell us nothing about the real successes and needs of schools."
The new initiative is likely to target those schools where up to 50 per cent of pupils get five good GCSEs, including English and maths.Reuse content