Exam boards will not set grade boundaries for GCSE English and English Language assessments in January 2013, Ofqual has confirmed.
The exams watchdog said this week that only raw marks will be available after next January's exams, with all work on setting standards and grading to be carried out following the June 2013 exams.
It means that "no grades or other information about aggregate performance" will be issued for the January 2013 exams or controlled assessments until June 2013 assessments have been marked.
Awards for both January and June assessments will be made at the same time, meaning that if a student "cashes in" all their units during the January season, their final grade will still not be released until August.
A statement from Ofqual said: "This change was first announced by Ofqual in its full report into GCSE English awarding this summer, published earlier this month. Ofqual's report identified a number of risks which could still affect 2013 students.
"Therefore this change is being made to protect those students as much as possible, and to protect the security and standards of the qualifications."
Students will still be able to make enquiries about results (EARs) for raw marks they receive in January assessments, but a further EAR cannot then be submitted for the same unit in June when the student receives their full qualification award.
The Welsh government has agreed to impose a special condition in parallel to Ofqual's.
The students completing their GCSEs in 2013 will be the final cohort to take these qualifications on a modular basis in England.
It comes as the watchdog prepares to defend its role in the English GCSE marking scandal at a Judicial Review, due to take place between December 18 and 20. The action has been brought by an alliance of schools, students, local authorities and unions which contends that the grade boundary changes unfairly disadvantaged tens of thousands of June students who received lower grades than those who sat in January.
Christine Blower, general secretary of the National Union of Teachers, said: "It comes as no surprise that Ofqual is now making efforts to avoid a repeat of this year's GCSE grading fiasco. It merely confirms the mess it has made in 2012.
"The fact remains that young people were let down. They, along with their teachers, worked in good faith to the parameters set in January. Ofqual continues to drag its heels and shift the blame, but a Judicial Review is set for 18 to 20 December. This cannot come soon enough for those young people whose prospects have been dashed by a mess of Ofqual's own making."