At present the defence can stay silent and the burden of proof rests with the prosecution.
Justice Minister Simon Power defended the regime yesterday, describing it as a case-management tool.
"I don't view it as an erosion of the right to silence. All you're doing is indicating in broad terms - not specific particulars - the areas that would be raised by the defence."
Mr Power is likely to focus his negotiations on the Act Party, as the Maori Party has joined Labour and the Greens in refusing to support the bill unless several aspects - including the disclosure regime - were removed. But, embarrassingly for the Government, the bill is unlikely to pass in its present form.
Other concerns in the bill include widening the scope of trials that can proceed when the accused is absent, and changing the rules around jury trials so several offences - including common assault and possession of a class A drug - would only be heard by a judge.
But Maori Party justice spokeswoman Rahui Katene said the party's main objection was the "removal of the right to silence".
"It's caused concern to a heck of a lot of people including the Criminal Bar Association and the Law Society and the Chief Justice. I think we're in good company there."
Chief Justice Dame Sian Elias, in her submission on the bill, described the pre-trial regime as "contrary to longstanding principle ... not to volunteer information that might help the prosecution".
Act parliamentary leader John Boscawen said the party's main concern was the right to silence, but he would not comment on whether party support depended on removing that provision.
Mr Power said he was open to the possibility of changing the bill.
THE RIGHT TO SILENCE
* The pre-trial regime in the Criminal Procedure (Reform and Modernisation) Bill has been described as eroding the right to silence.
* The defence would have to disclose all parts of a case in dispute to the prosecution before the trial.
* At the moment the defence can stay silent and the burden of proof for all parts of a case rests with the prosecution.
* Labour, Greens and the Maori Party want the regime removed from the bill. Act has expressed concerns. Only National supports it in its present form.