The first set of GCSE results since the government introduced a major shake-up of the system will be released tomorrow.

For some subjects, pupils will be graded with numbers, rather than the letter grades that have been in place for two decades.

Under the biggest shake-up of exams for a generation, traditional A* to G grades have been replaced with a 9 to 1 system, with 9 the highest mark.

English and maths - key GCSEs for all teenagers - are the first to move over, with other subjects following over the next two years.

It means that this year, students will be getting a mix of letter and number grades, with the new system making it difficult to compare results to previous years.

A local union spokesman claims the change makes the system is needlessly complicated.

The Department for Education says the grading switch, part of wider reforms designed to make GCSEs more rigorous and challenging, has been introduced in a bid to allow more differentiation between students, particularly among the brightest. Some education experts have predicted that this summer’s exams have been the most difficult in decades.

Ian Murch, Bradford Spokesman for the National Union of Teachers, told the Telegraph & Argus: “This new system will confuse people. There are also very different standards being applied to this year’s exams, which is likely to mean they have been very difficult for students.

“I think it will be a good example why you shouldn’t make changes to the exam system for no real reason.

“I think for the students who took them this year they will have been very difficult, and they have a reason to be upset about this. Although they can alter grade boundaries to reflect this, I think it makes these grades much less reliable.

“There is a constant desire by each new Secretary of State for Education to completely change the system.

“A lot of employers will know very little about this new system, and it will be difficult to make comparisons with previous years’ results. Dividing the grades into numbers and letters this year will confuse people.”

As in previous years, the Telegraph & Argus will be running a results day live blog from 8am tomorrow morning, featuring success stories, interviews with students, and photos from schools across Bradford and the surrounding areas, as well as exam results sent by schools.

Anyone who has a story or anything they want us to include on the blog can use the hashtag #bfdresults on social media or email newsdesk@telegraphandargus.co.uk.

There will be a story on the results in Friday’s paper, and a souvenir supplement with all the results we have been sent the following Wednesday.