Michael Gove is facing calls to make a statement in Parliament on resolving a growing row over the grading of GCSE English exams.
Gove is due to answer scheduled education questions from MPs at 2.30pm in the Commons but Speaker John Bercow may face a request for an Urgent Question to the Education Secretary if he does not ask to make a formal statement.
Labour's education spokesman Stephen Twigg yesterday urged Mr Gove to answer questions on the row.
Speaking on Sky News, he said: "Parliament comes back tomorrow and we expect him to come to Parliament and to set out what's going to happen because there is a basic unfairness here.
"If you were assessed in January you could get a grade C. The same quality of work, maybe even slightly better work, assessed in May and you would have got a D. That cannot be right."
The exam regulator says GCSE English exams were graded generously in January, but it found no problem with the boundaries set for June.
England's exams watchdog, Ofqual, is to set out its initial findings on the row over English GCSEs.