The government has unveiled plans to close the worst-performing schools in England and Wales unless exam results improve.
One fifth of schools are currently classed as under-performing, with 638 failing to attain five good GCSEs, including English and maths, for 30 per cent of their pupils.
Schools secretary Ed Balls unveiled the £400 million National Challenge initiative this morning.
Speaking ahead of the official announcement, he said the scheme would break the link between "poverty and results".
He told the Today programme schools would have between two and three years to turn things around and promised an adviser for every school.
"By the end of the summer term I want local authorities coming back to me with their plan school by school," he added.
Schools minister Lord Adonis has also suggested that pupils should spend their entire pre-university education in the same school.
He told the Daily Telegraph the government was considering trialling "all-through" schools in England and Wales.
The National Union of Teachers' acting general secretary Christine Blower said issuing school closure threats was not the way in which to improve standards.
"The National Challenge should be about saying to teachers that it is a career advantage to work in schools in challenging circumstances not a career threat," she explained.
"Teachers in these schools will have gone the extra mile for youngsters entering secondary schools, who may have started caring little about learning and education. For those youngsters to achieve four GCSEs, for example, may be a huge achievement, nothing in Ed Balls' target recognises that."