Eleven higher education institutions have refused to be inspected by quality audit teams that include students.
Earlier this year, the Quality Assurance Agency made a commitment to include students as full members of institutional audit teams in England and Northern Ireland, to work alongside senior academics or administrators. The move follows the introduction of student reviewers in Scotland in 2002.
More than 50 institutions have agreed to have students on their audit teams during the 2009-11 audit cycle.
However, because the change has been introduced halfway through the current cycle, the QAA has allowed universities to opt out of having student reviewers until the next cycle of audits begins.
From 2011, all QAA audit teams will have student members.
When the plan was first announced, some academics argued that including students could devalue the audit process because students were not truly "peers".
However, a QAA report last summer into a pilot scheme concluded that the experiment was a success.
A spokeswoman for the QAA said: "Institutions were given a choice as to whether they agreed to have students as members of their audit teams during the current cycle of audit. For those that did opt out, QAA did not ask for an explanation of reasons. However, it is thought that reservations may generally be about changing the audit arrangements midway through a cycle rather than objections to student involvement.
"This significant change puts students at the heart of the quality assurance process and reflects the commitment of the QAA and the higher education sector to engage students in the development of their own education."
Almost 100 students applied and a total of 58 have been recruited and trained to audit higher education institutions from January 2010.
Meanwhile, the QAA has launched a series of films that it says highlight the importance of students taking a leading role in assuring the quality of their own education.
These demonstrate the approaches universities have taken to engage students in quality assurance, and offer advice to students interested in getting involved.
Anthony McClaran, the QAA's new chief executive, said: "The messages we are receiving in these films show that more and more institutions are taking steps to engage their students in quality assurance processes and are seeing huge benefits. Engaging students allows institutions to gain a better understanding of what the student experience is like at that institution.
"Promoting student engagement is a high priority for the QAA, and I am pleased to see that, although there are a number of challenges for institutions, they are making great efforts. These films show that staff are clearly passionate about this area of work."