In its response to the higher education White Paper, the 1994 Group of research-intensive universities says ministers should go beyond current plans to relax student number controls, under which institutions will be allowed to admit as many AAB students as they can attract, once these students are deducted from their core quotas.
The group claims that the plans will harm provision of science, technology, engineering and mathematics (STEM) courses because many of these subjects have low levels of students gaining AAB grades.
Only 20 per cent of biology students had marks equivalent to AAB, while 40 per cent going into history or philosophy courses achieved those grades, it notes.
Widening the proposals to incorporate more students of a "similar level of achievement" would "alleviate many of the damaging effects" of the AAB changes, it says.
These deleterious effects would include less choice for students, damage to strategically important and vulnerable subjects, and disadvantages for poor students, the group argues.
"As an immediate measure in 2012-13, places for students achieving ABB+ at A level (rather than AAB+) should be uncapped," the group says. "But we stress that even an ABB+ policy should be an interim measure whilst moving to full flexibility in student numbers.
"This should be done as quickly as possible to avoid damage to the higher education system, which would be the result of only introducing competition to a small segment of the sector."
In its submission to the consultation, which ended on 20 September, the Russell Group calls for the relaxation of the AAB mechanism in certain subjects.
"(The 成人VR视频 Funding Council for England) may wish to consider whether a uniform threshold of AAB across all subjects remains the best approach or whether a more differentiated approach could be preferable," it says.
Secondary proposals in the White Paper to cut core student numbers by 8 per cent across the board and auction off those places to low-cost providers are also criticised.
"We simply do not believe that redistributing those student places ... will drive up quality or improve student choice," said Wendy Piatt, director general of the Russell Group.
The mission group also says that a Hefce teaching subsidy of ?1,500 per STEM student will not be enough to cover costs even when the full ?9,000-a-year tuition fee is imposed.
And it challenges a proposed move to post-qualifications applications, saying its members "need to be persuaded that the potential benefits...outweigh the disadvantages for students, as well as the costs and major upheaval involved for schools and universities".
Both groups ask the government to consider the impact of the reforms on postgraduate education, arguing that higher postgraduate fees and a lack of student loans act as barriers to the training of the next generation of academics.