Ministers in the Department for Business, Innovation and Skills are appointing a legal reviewer to consider decisions made by Professor Ebdon, outgoing vice-chancellor of the University of Bedfordshire, who takes up his new role in September.
Professor Ebdon has previously said that he could not rule out using the "nuclear option" of refusing universities permission to charge tuition fees of more than £6,000 a year if he deems their access plans for poor students to be insufficient.
A recruitment notice published by BIS says the reviewer - to be paid when required at a rate of £1,500 to £3,000 a day - will be needed if a university applies "for a review of the decision taken by the director of fair access on the approval, variation and enforcement of access plans".
Although someone had been appointed to the role in the past, there has been no reviewer in post since February 2010. The need for one now suggests that BIS expects Professor Ebdon to be far likelier than his predecessor, Sir Martin Harris, to confront universities on access plans - and also expects universities to fight back.
A BIS spokeswoman said: "The services of a reviewer were never called on, and therefore the previous arrangement expired unnoticed.
"The government is asking the director to take on more work with an enhanced budget, so everything associated with the Office for Fair Access arrangements is being looked at afresh to ensure that they are right going forward."
Liam Burns, president of the National Union of Students, said he hoped that the move was "an indication of the government's expectation that Offa will now be more critical of universities".
But instead of using "expensive reviewers", he said ministers "should give Offa the power and resource it needs to fulfil its role effectively".
Offa has "historically spent too much time jumping to the defence of universities rather than scrutinising them", Mr Burns said.
David Palfreyman, director of the Oxford Centre for Higher Education Policy Studies and co-author of The Law of Higher Education, said there were two possible explanations behind the reviewer appointment: "cock-up" (the post had been forgotten about) or "conspiracy".
The conspiracy theory runs that BIS could be expecting trouble if Russell Group universities "get stroppy" about Offa attempting to control admissions.
Mr Palfreyman said that while admissions, as distinct from applications, were "well beyond" Offa's powers, the Liberal Democrats "seem to be nudging the boundaries".
The appointment of Professor Ebdon as Offa director caused huge controversy. The government named him its preferred candidate in January, and the appointment was forced through in February after Conservative MPs on the BIS select committee voted against it. The Russell Group and Michael Gove, the education secretary, were seen as being strongly opposed to the move, and Professor Ebdon was criticised as a "social engineer" by some in the press.