Tens of thousands of students in England will receive their A-level and GCSE results this month after exams were cancelled for the second year in a row due to coronavirus.
Sir Keir said Prime Minister Boris Johnson and Education Secretary Gavin Williamson had failed to act early enough to ensure this summer’s results operations run smoothly.
He said: “I have a very vivid memory of the day I got my A-level results – of the pressure, nerves and worry that my entire path could be determined by what was on that sheet of paper.
“It frustrates me immensely that this week’s big moment in so many young people’s lives is being risked by the chaos and incompetence at the top of this Government.”
The Opposition called for the Government to work with universities, colleges and employers to ensure youngsters can move on after receiving their grades.
Labour also demanded a functional appeals system and support for teachers and education leaders.
Sir Keir added: “This abject refusal of Boris Johnson to get a grip has created huge extra stress for students and baked unfairness into the assessment process.”
Students in England, Wales and Northern Ireland will receive their A-level and GCSE results in the same week in August, with A-levels on Tuesday August 10 and GCSE results on Thursday August 12.
Last summer, the fiasco around grading led to thousands of A-level students having their results downgraded from school estimates by what Mr Johnson dubbed a “mutant algorithm” before Ofqual announced a U-turn.
A Department for Education spokesman said: “We recognise the unprecedented challenges pupils and students have faced over the last year and a half, and have been working with Ofqual, universities and other providers for months to ensure as many students as possible can progress.
“This includes putting in place a rigorous system to ensure grades are fair, and this week we have adjusted the cap on medical and dentistry places so that more students than ever will have the opportunity to study on these courses in 2021.
“A record number of students have applied to university this year and are taking the next steps in their lives towards securing exciting and rewarding careers – after an extraordinary and challenging period. Ucas, the admissions service, is predicting that over 80% of people will get into their first choice of university.
“Exams are the best form of assessment but in the absence of those this year there is no-one better placed to judge young people’s abilities than their teachers, who see them day in, day out.
“Teachers have assessed multiple pieces of work, in turn giving students multiple opportunities to show what they know and perform to their best.”