Susex Runner: In my subject (science) the "coursework" has been in school, supervised and mostly in exam conditions (apart from the experiment bit). The reason the grades are lower is that the exam boards have followed Gove's explicit instructions to "pass" fewer pupils. The grade boundary has simply been made higher. In a two year course, some of the coursework assessment would have been done a year ago. Pupils with a safe result attained then have simply been awarded a lower grade now.
By all means be honest and say that we want fewer passes so we are raising the pass mark, but, as savi says, do it at the start of the course, not retrospectively.
If I had paid the equivalent cost to enter a 10k I would want my money back if the course was not only made longer, but there were no distance markers and I wasn't informed of the change until after I had finished.