Mr Willetts' comments come after Telegraph reporters filmed staff at an agency in China saying it could help a student get into certain UK universities with three C or B grades at A-level.

BBC: Willetts warns universities over foreign student grades

At the Jay Street station, Bedford-Stuyvesant student Shaniqua Robinson, 18, who rides the C to school in Queens, cataloged the train's failings.

WSJ: MTA Moving to Phase Out the C Line's Clunkers

The C-plus prevented Thode, an otherwise A student, from going on to the next class and advancing in her professional therapist studies, according to The Express-Times of Easton.

NPR: Pa. Grad Student Sues, Says C-Plus Cost Her $1.3M

They indicate the minimum score on each of the four subject tests for a student who has a 75% chance of earning a grade of C or higher or a 50% chance of earning a B or higher in a typical first-year college course.

FORBES: High School Grads Even Less Prepared But At Least Doing Better In Math And Science

He added that AQA had reneged on guidance to schools about the standard needed to achieve a C grade and said that this had hit the most vulnerable part of the student population hardest.

BBC: English GCSE: Senior exam board figure quits AQA