Revealed: Under-performing secondary schools in the Black Country and Staffordshire

The schools – three in Walsall, three in Sandwell, two in Wolverhampton, one in Dudley, one in Staffordshire and one in Wyre Forest – are deemed to have fallen below the Government's performance threshold in 2017.

This means pupils are failing to make enough progress across eight subjects, with particular weight given to English and maths, according to the Department for Education.

The list of schools failing to meet the floor standards in the region includes Norton Canes High School, The Holly Hall Academy in Dudley, Holy Trinity School in Kidderminster, the ACE Academy in Tipton, Walsall Studio School and Brownhills Schools.

Wodensborough Ormiston Academy in Wednesbury, Health Futures UTC in West Bromwich, Willenhall E-ACT Academy, Wednesfield High Specialist Engineering Academy and West Midlands Construction UTC in Wolverhampton have all also been highlighted as failing to hit the required standard.

The figures show that nationally about one in 12 children – a total of 260,783 – are now being taught at under-performing secondaries.

This is a rise from 206,991 in 2016.

The increase comes amid major changes to England's exams system, including the introduction of a new grading system, which has meant the data includes English and maths GCSE results awarded new 9 to 1 scores while other subjects received traditional A* to G grades.

School leaders said the new grading system affecting English and maths has complicated the way school performance is calculated, as it has to be worked out using a combination of old and new grading systems.

Geoff Barton, general secretary of the Association of School and College Leaders (ASCL), said: "As the DfE itself says, these changes are the main reason why there has been an increase in the number of schools which are deemed to be below the 'floor standard' for Progress 8.

"It is extremely unfair that more schools find themselves in this situation because of complex changes to the way in which this is calculated.

"Our message to the DfE, trust boards, governors and inspectors is to avoid leaping to judgement on the basis of these performance tables. They only tell us a limited amount about the true quality of a school."

Schools are judged against a measure called Progress 8 which looks at the progress a pupil has made between the end of primary and the end of secondary school, and results across eight GCSEs compared to their achievement of other youngsters with similar abilities.

A secondary is considered to be below the government's floor standard if, on average, pupils score half a grade less (-0.5) across eight GCSEs than they would have been expected to compared to pupils of similar abilities nationally.

The DfE insisted that where schools have fallen below the floor standard, the data is 'a starting point for a conversation about school improvement'.

Schools Minister Nick Gibb said: "The attainment gap between the most disadvantaged pupils and their peers has narrowed by 10 per cent since 2011 and more disadvantaged pupils are studying the core academic subjects, ensuring they have the knowledge and skills they need to make the most of their lives."