The Justice Minister David Ford has defended the new rates set for solicitors and lawyers working on legal aid cases in NI.
Defence lawyers have threatened to stop work on serious criminal cases after the changes came into force on Wednesday.
They said the new regime would not allow them to do their jobs properly.
Justice Minister David Ford said the move would save £18m.
Under the rules set out by Mr Ford, enhanced rates paid out in 'Very High Cost Cases' are to end.
Fees to solicitors in standard cases are to be reduced by 25% under changes in the Legal Aid for Crown Court Proceedings (Costs) (Amendment) Rules. Barristers' rates will also drop by 20% as part of the changes.
Defence solicitors signalled on Wednesday they will not be there to represent clients facing charges up to murder when they pass to the crown court.
With barristers depending on these lawyers for their instructions, it means any legal representation is highly unlikely unless a solution is reached.
However, preliminary enquiry hearings will still go ahead at Magistrates Court level.
Belfast solicitor Eamon McKenna withdrew his services on Wednesday after one of his clients, who was appearing in Belfast Magistrates Court, was returned for crown court trial on charges of rioting and throwing a petrol bomb.
'Effect on criminal justice system'
He said the changes would not allow solicitors to do their "jobs properly".
"The principle concern at present is in relation to the effect this has on the system of criminal justice," he said.
"We believe such dramatic changes will not allow the courts to ensure fair trails for those accused of serious crimes at Crown Court level.
"We would say those levels have been set at such a level that don't allow us to do the work that's required to defend a person properly."
Mr Ford said the lower fees were necessary.
"The key issue has to be that the Legal Aid budget last year was £104m, against a budget of £85m," he said.
"We all know the spending cuts which are being faced and we have to get it down to a budget in two years of £75m, based on the cuts that are being imposed on us.
Mr Ford accepted the cuts were quite steep.
"I accept that this is hard for anyone to take on board, but I think we have to look at what is happening," he said.
'Reality of world we live in'
"I suspect there are some people in Kilkeel waking up this morning who'd be very happy if they were only taking a cut of 25%.
"That's the reality of the world we live in at the moment. We have legal aid services which were allowed to spiral out of control."
Mr McKenna estimated that the loss to his own practice would be higher than 25%.
"It is only 25% in relation to standard fee cases," he said.
"The real cost has been calculated at 53%.
"In terms of my own firm, I would believe it would be more likely, in around 60%."
The justice minister said he hoped the legal profession would accept the changes.
"When you ask as to whether people will withdraw, I certainly hope that lawyers will not withdraw, and as I understand it, on Wednesday, there was one case in which the solicitor withdrew.
"There were several cases which went on in other parts of NI, in which the solicitor stayed on record, to use the jargon, and Crown Court legal aid has been granted, so I think there is no indication that there is a widespread withdrawal from this type of work at this stage."
Eamon McKenna said his firm would be refusing to carry out legal aid cases which were returned for trial in the crown court.
"At the moment we are forgoing the fees in relation to these cases," he said.
"I was extremely sad to have to make that decision. I had considered the documentation in relation to this very carefully."