Justice Minister David Ford has defended his decision to lower legal aid fees amid a protest which left 140 defendants without legal protection.
"Solicitors and barristers have to recognise the reality of the pressure the public purse is under," he said.
Mr Ford said he was determined to preserve defendants' access to justice. But the legal aid bill was too high.
However, Pearse McDermott of the Solicitors Criminal Bar Association said defendants would suffer.
Solicitors have refused to take on more than three quarters of criminal legal aid cases due to start in NI during the past six weeks.
More than 140 defendants have been left without legal representation because of the protest over lower legal fees.
"We don't want to be on strike. We don't want to be withdrawing our services... We are professional people who want to be representing our clients," Mr McDermott said.
"The problem is we cannot represent our clients effectively, we cannot guarantee that they receive a fair trial, we cannot do the proper presentation on the figures that are put forward at present."
Mr McDermott said the justice minister and the court service should take "a reality check".
He claimed the proposed rates meant defendants would not be entitled to get a fair trial and solicitors' firms would have to consider laying off staff.
However Mr Ford said his department could not continue paying fees at the previous higher rates - the amount was "unsustainable".
"We all know the difficulties that pubic finances are under. The reality is that the legal aid bill over the last 10 years has gone from £38m to £105m," he said.
"We have a budget which has to reduce it to £75m over the course of the next spending year period."
Mr Ford said he was working to ensure that the same access to justice would be preserved to defendants.
"What I cannot do is pay solicitors and barristers the amount that they want to be paid."
Mr Ford said lawyers had to recognise the pressure that the public purse is under.
Lower fees were introduced in March. Mr Ford and his officials say they are fair and generous.
The Law Society, which represents solicitors in Northern Ireland, claims the new fees make proper preparations impossible and threaten the right to a fair trial.
It passed a motion in March stating that if a solicitor believes the proposed level of payment is insufficient to enable them to conduct the work to the proper standard, they should not accept the case.
The Bar Council, which represents barristers, has also passed a motion rejecting the fees, and supporting the action by solicitors.
Legal aid in Northern Ireland is 20% more expensive per head of population than in England and Wales.
The bill for last year was more than £100m.
David Ford met the new justice committee at Stormont for the first time on Thursday and said that figure was not sustainable.
The head of the court service, David Lavery, reinforced that message.
"What we can't do is simply sustain a system that enriched a small number of lawyers in this country," he said.
So what is the difference in fees?
According to the court service, the new NI fees mean that the combined legal bill for solicitors and barristers in a typical three-day Crown Court trial for an offence such as drugs or common assault would be almost £5,000.
For the same type of case in England and Wales, the fees would be just under £2,800.
For a five-day trial for an offence such as murder, the combined legal aid fees here would be more than £20,700.
In England and Wales, the total would be more than £19,200 almost £1,500 lower than NI.
On Thursday, the justice committee backed the minister and approved the new fees structure.
Mr Ford has written to more than 500 legal firms asking if they are willing to take on work at the new rates.