Students are obtaining degrees without having to sit the most difficult parts of their courses, quality watchdogs have found.
The problem was highlighted this week by the Quality Assurance Agency, which called on Leeds Metropolitan University to close a loophole in its assessment rules that allows the "tactical avoidance of challenging modules".
An external examiners' report at Middlesex University also warns that students can "play the system" and "withdraw tactically" from certain courses to avoid lower grades.
In the audit report of Leeds Met published this week, the QAA concludes that it has "broad confidence" in the university's management of academic standards.
But it advises the university to "proceed quickly to review its assessment regulations relating to student progression" after warnings over several years that students can exploit its rules.
The report says that the university's rules allow students to take the second year of their degree even if they have failed 15 out of 120 first-year credits.
"Several external examiners have expressed concern about this on the grounds that it exposes the university to the risk that the full range of learning outcomes may not be achieved and it permits the tactical avoidance of challenging modules," the QAA says.
The report adds that "similar concerns" had been raised in two earlier subject-level QAA reviews, "and several staff... indicated continuing concern about the unintended effects of this regulation, stating also that an anticipated review had not yet taken place".
In its published response to the audit, Leeds Met says: "Of the specific areas that the QAA suggests the university reviews, there has been significant progress since the visit. We have completed the review of our progression regulations; new regulations will be approved by the academic board for introduction in September 2005 for the academic year 2005-06."
Students will be required to gain a minimum standard in all modules.
At Middlesex, a 2004 external examiners' report on a computer communications degree, published on the Government-backed Teaching Quality Information website, raised similar concerns.
The unnamed examiner, from Leeds University, said that final degree awards were calculated on the basis of a "prescriptive algorithm based on the aggregate number of modules at each performance level (first, upper second, etc)".
The examiner said that while this is "very fair to students... on the other hand, some students are able to 'play' the system a little, withdrawing tactically, for example, to avoid a lower classification, or not completing work as well as they could when a certain degree grade is already ensured".
Middlesex said that its system was fair and transparent, and added that while students could "ease off" in their final semester, it was a risky strategy as they could be penalised for too many low pass grades.