Revealed: The North East schools said to be 'under-performing' in new Government tables

One in eight of England's mainstream secondaries - 365 in total - fell below the government's minimum standards in 2017, according to new statistics.

This is up from 282 schools, just under one in 10 - the year before.

According to Press Association analysis of the data, it means 260,783 schoolchildren are now being taught at under-performing secondaries - about one in 12 (8.6%), compared to 206,991 (6.8%) in 2016.

Schools fall below the government's performance threshold if pupils fail to make enough progress across eight subjects, with particular weight given to English and maths.

There were 365 state-funded mainstream secondary schools in England that did not meet the Government's floor standard for performance in 2017.

The North East schools contained on the list are:

Northumberland CofE Academy, Ashington

The Blyth Academy, Blyth

Longfield Academy of Sport, Darlington

Polam Hall School, Darlington

St Aidan's Church of England Academy, Darlington

Belmont Community School, Durham

Fyndoune Community College, Durham

Durham Community Business College for Technology and Enterprise, Durham

Heworth Grange Comprehensive School, Gateshead

Thomas Hepburn Community Academy, Gateshead

Laurence Jackson School, Guisborough

High Tunstall College of Science, Hartlepool

Kepier, Houghton le Spring

Hetton School, Houghton le Spring

Unity City Academy, Middlesbrough

Middlesbrough College, Middlesbrough

Hillsview Academy, Middlesbrough

Discovery School, Newcastle upon Tyne

Walbottle Campus, Newcastle-upon-Tyne

NCG, Newcastle-upon-Tyne

Norham High School, North Shields

East Durham College, Peterlee

Huntcliff School, Saltburn-by-the-Sea

Tyne Coast College, South Shields

South Shields School, South Shields

Whitworth Park School and Sixth Form College, Spennymoor

Tanfield School, Specialist College of Science and Engineering, Stanley

Academy 360, Sunderland

Red House Academy, Sunderland

Thornaby Academy, Thornaby

Washington School, Washington

The Department for Education (DfE) said the rise in under-performing schools is because of technical changes to the points system used by government statisticians to calculate a school's performance.

The rise 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 9-1 grades while other subjects received traditional A*-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 in today's statistics, 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 their 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 highlighted a narrowing gulf between the results of rich and poor pupils.

"The attainment gap between the most disadvantaged pupils and their peers has narrowed by 10% 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," he said.