Liberal Assembly member Giulia Jones and Labor backbenchers Bec Cody and Michael Pettersson were unable to come to a consensus on the legislation, although they separately concluded the external review provisions were deficient.

According to the draft legislation, injured parties can only apply for an external review after their claim has been internally reviewed by the insurance company.

And while the Magistrates Court was floated as a prospective means of challenging an insurer's decision, the government is yet to nominate an avenue for external review.

Committee chair Mrs Jones filed an excoriating dissenting report that described the bill as an "abject failure at its most basic intent to provide Canberra road users with an insurance product that will compensate them for injury incurred".

"The bill promotes the interests of large insurance corporations at the expense of injured innocent people," Mrs Jones wrote.

"A substantial majority of the victims injured will receive significantly less, and indeed they will be at the mercy of the large insurance corporations to a much greater extent under the proposed bill than at present."

Mrs Jones said the new scheme placed a significant administrative and negotiating burden on injured people by cutting lawyers out of the equation.

While lawyers can currently deduct fees from their client's final settlement, there is no provision for this in the new scheme.

"As a result the injured person will have to negotiate directly in most cases with the insurer themselves. This puts them at a significant disadvantage as compared to the current system," Mrs Jones said.

Unlike similar legislation in NSW, the bill does not include a clear dispute resolution process.

"It is of grave concern to many that the bill is planned to be passed through the Assembly and yet there is no explanation of what dispute resolution process will be available," Mrs Jones said.

Mrs Jones called for the Assembly to kill off the bill, and for the government to go back to the drawing board to devise a scheme that "benefits the community as a whole and not simply insurance companies". Mr Pettersson and Ms Cody found the reforms were justified, but recommended some modifications.

Ms Cody and Mr Pettersson said the processes for external review outlined in the bill were "clearly insufficient" and urged for more detail "to make clear that this is an integral component of the scheme".

They also said the ACT Civil and Administrative Tribunal should provide external reviews, as the cost of appealing a decision through the ACT Magistrates Court could be in the thousands of dollars.

"While it is not ideal to have a system that requires almost everyone to get a lawyer in order to get what they need – as is currently the case – fair and just administration of any new system will require that people can still seek legal review of decisions if they choose to, and be legally represented when they do," they said.

"Canberrans should not be prevented from pursuing external review of decisions which may have lower dollar impacts but significant benefits in terms of their overall recovery or quality of life, simply because of the costs involved in doing so."

Mr Pettersson and Ms Cody also called for the ACT Civil and Administrative Tribunal to be given the power to make legal cost orders against the losing party in external review cases to deter insurers from denying reasonable benefits.

They said the government should review insurer profits within three years of the scheme coming into effect and move to cap insurer profits, as other jurisdictions have done, if they are shown to be above fair and reasonable levels.

However the ACT Law Society dunked on the prospective review as a "pathetic non-decision".

"No doubt the government, backed by the insurers, will seek to bulldoze its inequitable and flawed scheme into law," president Chris Donohue said.

The inquiry into the bill was concocted by Labor as a way to head off potential problems with the legislation, which they wanted to pass this year.

The new compulsory third party insurance scheme was designed by the ACT's first citizens' jury and will replace the existing at-fault, common law system.

Under the new scheme anyone injured in a motor vehicle accident will be able to access treatment, care and income support for up to five years, with the most seriously injured and the not-at-fault able to access additional benefits.

But while Canberrans are expected to save between $91 and $171 on their yearly premiums, the scheme severely caps the amount of compensation injured people can claim and would cut payments for people guilty of infringements like failing to wear a helmet.