More than 300,000 teenagers left secondary school last year without five good GCSE grades, including English and maths, official figures have shown.
One in seven schools are failing to ensure that 30% of their pupils achieve at least five C grades, including the two core subjects.
Ministers announced last June that they wanted no school to be in this position by 2011.
Statistics published on Wednesday by the Department for Children, Schools and Families show that 440 schools are currently falling short of this target, down from 631 last year.
Schools that fail to meet this target are judged to be under-performing and fall under the Government's controversial National Challenge initiative.
They could face closure or being turned into an Academy if their results do not improve.
Wednesday's figures show that 47.6% of the 653,045 pupils who took the exams last summer achieved five or more good GCSE's (A*-C) including English and maths, meaning about 340,000 did not reach this benchmark.
At the 63 academies where pupils took exams in August, 35.6% of pupils achieved this target, while 60.4 got five C grades in any subjects.
The statistics show that at all schools, 65.3% of pupils achieved at least C grades in any five subjects, while 91.6% of pupils are gaining five or more GCSEs grades A*-G, which is considered a pass.