Shadow education secretary Ed Balls this week accused his opposite number Michael Gove of abandoning the country's worst-performing schools.
Giving his keynote address at the Labour conference on Wednesday, Mr Balls said the Education Secretary has broken his promise to identify the 100 worst schools in his first 100 days in government and put them in the hands of top-performing heads.
Mr Balls defended his party's performance over the past 13 years and attacked the Coalition Government's plans for school reform as the most "socially divisive education experiment for 60 years".
The Labour MP said that Mr Gove's decision to drop the National Challenge programme and extend academies to schools rated outstanding by Ofsted would "entrench division and inequality".
Mr Balls said: "I am proud that we transformed hundreds of schools across the country. And today we have not one in two schools below our National Challenge standard as in 1997, but just one in 20 - schools Michael Gove has shown he will now abandon."
When the Labour Government introduced National Challenge three years ago, nearly 700 schools failed to hit the Government's floor target of 30 per cent of pupils gaining five A* to C grades including English and maths.
In the following years, that number dropped to 439 schools in 2008, and 247 in 2009 or less than one in 12 schools. According to figures released by Labour this week, a survey of the 102 National Challenge schools showed that only one in 25 schools missed the Government's floor target and just one school did not improve its results this year.
The National Challenge attracted huge criticism when it was introduced in 2007, with teachers leaders claiming it "named and shamed" schools and placed them under too much pressure to turn themselves around in a short period of time.
But general secretary of the NASUWT Chris Keates said: "The programme did attract a lot of bad press when it was introduced for the amount of pressure it put schools under, but what people did get was extra resources to help them address the issues they were facing.
"That is the element Michael Gove has abandoned. He is not giving the support or resources that those teachers need, and they will find themselves struggling even more now that support has been dropped. That is why we oppose these changes to structure rather investing in teachers and support staff and in schools themselves."
A source close to Mr Gove said: "Balls' record is clear: a huge gap in attainment between the richest and poorest students, discipline out of control and standards falling against the best in the world.
"The Coalition Government is giving teachers the powers they need to keep discipline, reversing the devaluation of the curriculum and exam system and introducing a pupil premium which will mean extra money for the poorest pupils, a policy which Ed Balls opposed."
The source added: "We are working closely with successful providers to identify new projects where academies will replace underperforming schools, to add to the substantial range of projects already in progress."