Falling numbers of lawyers willing to do legal aid cases could reduce access to justice for some defendants, according to the Law Society.
The legal aid system is supposed to help low income people pay for the high cost of legal representation, but lawyers are pulling away from it in growing numbers.
A publication by the Law Society has found a 54 percent drop in the number of lawyers willing to take on civil law causes under legal aid arrangements in the past five years.
There was a 25 percent drop for family law, and 12 percent for criminal.
The Law Society publication added there was also a decline in the number of lawyers prepared to do mental health and refugee cases under legal aid.
This steady fall off would hurt defendants and litigants in the long run, according to Liz Bolger of the Law Society.
"The availability of lawyers dictates the access to justice for people who might be in need of legal aid," she said.
"If there are fewer providers, then the providers remaining are going to be much busier and less accessible as time goes on."
Allister Davis is a lawyer in Christchurch and said many lawyers just could not afford to work under legal aid arrangements.
"You get $215 plus GST for administration, and you get $75 for the case management memorandum," he said.
"You then get $180 for a trial which could last for one hour or could last a day.
"And then you get $100 for sentencing. Ultimately that is just over $500."
The figures showing lawyers voting with their feet came out in a written reply to parliamentary questions by Green MP David Clendon.
The response came from Associate Justice Minister Simon Bridges.
Two months ago, Mr Bridges boosted the legal aid budget by $96 million over four years, saying legal aid helped people apply for protection orders, agree on parenting arrangements, settle employment disputes, and other things.
Liz Bolger said this extra money had helped solve some problems, but there was more to it than just the cash.
"Legal aid is often difficult to manage," she said.
"There is a lot of correspondence involved, there can be a lot of coming and going with the ministry in terms of amendments to grants, or questions which are asked about particular issues, or disbursements to experts. It all takes time."
The fall off in commitment to Legal Aid is explained in part by the establishment of a Public Defenders Office, which has taken about half the criminal law work away from legal aid lawyers.
But a lawyer who does a lot of legal aid work, Tony Ellis, said there were other problems.
"The Public Defenders Office does criminal work, it does not do family work and it certainly does not do civil work," he said.
"So it can be extremely difficult for people who can't afford to bring a civil case to find a lawyer."
Dr Ellis said there were only about 200 lawyers doing civil law legal aid out of 13,000 lawyers holding practising certificates around the country.