The Government is struggling to find enough support in Parliament to pass legislation for what it says would be the most major reforms of criminal justice in 50 years.
The Criminal Procedure (Reform and Modernisation) Bill aims to speed up the criminal justice system and would result in fewer jury trials.
The the legislation survived its first vote and has been through a select committee.
But Justice Minister Simon Power says at this stage, only the National Party is committed to support the bill at its next vote. He says he is still in discussion with the Government's support parties.
Mr Power says they have expressed some concerns, including the future of the right to silence and the move to have defence lawyers make known in advance broadly what areas they will argue in court.
However, the minister says he is confident the Government will able to work through the issues.
ACT and the Maori Party supported the bill to its select committee stage but now say they have reservations.
The Law Society says it objects to several parts of the bill. President Jonathan Temm told Checkpoint the legal system is in need of reform but is concerned about some aspects, including limiting the right to trial by jury, and says more discussion is needed.