The government body responsible for monitoring "equal access" to universities charging £9,000 tuition fees has had to double its staff and appeal for more funds amid the chaos caused by the recent reforms.

The number of universities declaring that they wish to charge students the highest amount from next year has caught ministers by surprise, with the majority of institutions planning to charge more than £7,500 a year.

As a result the Office for Fair Access (Offa), which has responsibility for ensuring those universities recruit from all parts of society, has had to engage in emergency budget negotiations with the Department for Business, Innovation and Skills as an unexpected number of universities have informed them of their intention to charge the highest fees.

David Barrett, Offa's assistant director, admitted his "very small" organisation was still in discussions with the government over its budget and had to take on two additional permanent staff and two casual staff to cope with the work load.

Friday was officially the day by which universities had to inform Offa if they intended to charge more than £6,000 for tuition, but Barrett said paperwork was expected to flood in over the coming week. He also admitted the 11 July deadline by which Offa is due to pronounce its satisfaction or otherwise regarding universities' plans to ensure equality of access may need to be flexible.

"The department has given us some additional resourcing and we have got some additional temporary resource from the Higher Education Funding Council for England (HEFCE)," Barrett added. "The 11 July deadline is still our intention.

"If there were extremely long and protracted negotiations with lots of institutions, then it is possible that some won't meet that decision date, but my firm belief is that we will be able to make that for all institutions.

"We are taking on some more staff and have temporary support from HEFCE, who support us in a service-level agreement in any case. The extra support is set up to be in place early on in the process and was negotiated with the department recently. There are contingencies in place as well."

Offa has only three full-time staff plus a part-time director and a part-time office worker, but an additional two full-time and two temporary members of staff will soon be drafted in.

The £500,000 budget set aside for Offa is expected to be doubled, adding to the spiralling costs to the Department for Business, Innovation and Skills.

Ministers had claimed that maximum £9,000 fees would be the exception. Long-term financial modelling carried out by the Treasury was based on universities charging an average of £7,500.

But it is feared a huge funding black hole will be created as the government struggles to provide student loans to cover the cost of higher fees. If this is exceeded, it is feared the loans bill will reach unsustainable levels.

A BIS spokesperson said: "In our letter of guidance to the director of Fair Access, issued in February, we asked that he should be more challenging and demanding of universities seeking to charge fees above £6,000.

"We have always made it clear to the director that, if he felt additional staff were needed to deliver the strengthened regime of access agreements, then we would support his request."

Shadow universities minister Gareth Thomas said: "This is just the latest sign of how badly the tuition fees fiasco has been handled. David Cameron and Nick Clegg failed to listen to independent experts who were warning even before the fees vote that allowing tuition fees to treble would cause problems they hadn't properly thought through."