Teachers, unions and councillors from the Calendar region will travel to the Royal Courts of Justice today for the start of the judicial review into GCSE marking in the summer.
They are members of the "educational alliance" which has brought the case to court
Almost 400 individual cases were involved in the bid for a judicial review. Mr Justice Cranston decided there should be an open court hearing after privately considering the merits of the application for permission to seek a review.
The alliance is challenging a decision by the exam boards to raise the boundary needed to get a grade C between January and June, as well as what they claim was a failure by Ofqual to address the situation. It claims that as a result of the decisions an estimated 10,000 pupils who took their English GCSE exam in June missed out on a C grade.
A statement of claim submitted to the high court said: "The decisions have prejudiced the life chances of thousands of children. The immediate effects of the decisions include children being unable to progress in education, losing vocational opportunities and jobs and being unable to gain employment.
"The children affected by the decisions were entitled to be treated in a fair, consistent and rational manner by the defendants. They were not. The decisions are incompatible with the most elementary principles of fairness, rationality and good administration. They are unlawful and should be quashed."
Councillor Judith Blake, executive member for children's services in Leeds, who wil be attending today, said:
"Thousands of young people up and down the country have been affected by this grading fiasco and it is on their behalf that we all welcome the start of the Judicial Review.
"We are determined to get a fair decision for these young people, which is why we have pushed for the judicial review to take place. I hope that good sense will prevail and that it results in a positive outcome for those that have been unfairly affected."