Ofqual said it is closely monitoring the marking of a Pearson Edexcel A-level maths paper after a petition demanding a review surged past 15,000 signatures in less than 24 hours. The regulator moved after students said Wednesday’s paper one was far tougher than they expected.

The petition was created on Wednesday, the same day students sat the exam, and quickly became the focus of complaints from those who said the paper left them overwhelmed and uncertain. For many, the issue was not simply that it was hard. They said it was significantly more challenging than any past papers they had worked through.

The scale of the response is what gives the dispute weight. In less than a day, more than 15,000 people had signed the petition, which argues that the pure mathematics paper demanded multiple layers of reasoning, extended algebraic manipulation and unfamiliar approaches. It also says the difficulty hit lower-achieving candidates disproportionately and that students deserve grades that reflect their mathematical ability rather than the unusual difficulty of one paper.

That argument matters because A-level maths grades are decided through a marking process that can shift if a paper proves harder than expected. Ofqual said its priority was ensuring students’ grades are a reliable indication of what they know, understand and can do. Pearson, which runs the exam, said every paper is developed with input from experienced senior examiners and rigorously checked to ensure it reflects the course and meets required standards.

Students, though, have pushed back on that reassurance. They said the paper felt unlike the material they had prepared for over two years, with the petition saying many had spent countless hours attending lessons, completing independent study, working through past papers, attending revision sessions and making personal sacrifices to get ready. Pearson said it reviews statistical data and expert judgment when setting grade boundaries, and said that if a paper is more difficult than previous years, the boundaries will be set to reflect that.

The unresolved question is whether that will be enough for the students who signed. Ofqual, England’s exams regulator, has not ordered a review, but its close monitoring leaves the door open to a grading adjustment if Pearson decides the paper really was harder than the run of previous years. For now, the pressure is on the marker and the boundary-setting process, where the final answer to the petition will be written into grades rather than statements.