I've anecdotes from two university lecturers on different courses. They both want some form of external moderation. its what happens for Postgraduate degrees after all.
What they report is horrifying:
* Essay writing skills are lacking, "its at GCSE level"
* Students contesting any form of criticism - they go via the official channels to argue why they should get a good grade. All schools are tied up in multiple tribunals with existing staff. Often its easier just to pass the student.
* In some cases, students are SUING the university for poor grades
* Plagiarism is commonplace. There is an automated plagiarism detection mechanism for electronic submissions - but they are turned off or ignored as it's so rampant. People literally copying from Wikipedia or copy and pasting from papers to make their own work. Wikipedia copying is especially used for definitions, e.g. "Hacker News is a social news website focusing on computer science and entrepreneurship...."
* Students don't see that their education is also their own responsibility, and see it as a purchase. Give me what I pay for.
* Students who don't turn up to classes and seminars demand the same grades as those who do.
* Hundreds of students email lecturers asking for help with their work (much more numbers and frequency than in the past).
They both despair as they see education standards falling, and theres not much they can do. They don't want to be sued by the students, nor do they want to spend all their time in tribunals, they are educators first. They see their own institution as being of very poor quality.
To me - I would look at a league table of education quality for UK universities. There isn't one, you cant compare. Previously a good chance of good education was the research output of a department, or the references of the teachers. But this, as my associates report don't mean anything anymore.