GCSE results across Oxfordshire have dipped to their lowest level since new performance measures were brought in.

The Government has released provisional figures for teenagers' attainment in this year's exams, revealing the county's overall picture for the first time as well as 'worrying' A-Level results.

Individual school results published by the Oxford Mail in August suggested students had successfully weathered the storm of major GCSE reforms, but the Department for Education (DfE) table tells another story.

The average 'Attainment 8' scored achieved by pupils in Oxfordshire dropped to 47.4, down from 50.4 last year.

Attainment 8 measures students' average GCSE grade across eight subjects including English and maths, adding up each of their new numerical grades from 9-1, which were introduced this year.

The Oxfordshire average hovers above the national average of 46.1, but is the worst performance in the three years since Attainment 8 scores were first phased in.

The DfE, which released the statistics last week, insisted: "These decreases are as expected following changes to the point scores assigned to grades.

"The percentage achieving [a pass] in English and maths is stable compared to equivalent 2016 data."

Changes to the system this year affected maths, English language and English literature, with students awarded numerical grades of 9-1 –with nine being the highest – as opposed to the traditional letter grades of A*-G.

The shake-up also made course content tougher, removed modules and made assessment exam-focused.

Teachers previously told the Oxford Mail students felt like 'guinea pigs' because of the changes, which will be rolled out in coming years across scores more subjects.

Just 47.7 per cent of Oxfordshire pupils achieved a pass (grades 9-5) in maths and English this year, compared to 65.4 per cent passing (with the equivalent A*-C grades) last year.

Students still outperformed the national average of 42.4 in those two subjects this year, however.

Education expert and county councillor John Howson said: "We clearly expected a drop - what is important is if we dipped more or less than other parts of the country.

"There were always going to be turbulent transitional years and we have got to decide what we are trying to measure; we need a degree of consistency to see if we are improving."

He said funding pressures posed an extra challenge for schools as they try to boost outcomes.

Reforms in A-Level exams also caused concern for both teachers and candidates in Oxfordshire prior to results day.

Freshly-released provisional figures show the percentage of the county's state schools students achieving at least two A-Levels were on par with the national average, at 76.2.

But professor Howson said certain results were 'not as good as they should be', adding: "I'm quite worried about our A-Level results. I think we need to take a serious look at our A-Level position."