NSW Senator Hollie Hughes has not ruled out voting against her government when legislation to mandate independent assessments is brought to parliament, declaring she's a "mum first, a senator second".

Her intervention came as Australia's disability discrimination commissioner labelled the proposed assessment system as "unsatisfactory" after he participated in a trial.

NDIS Minister Linda Reynolds said on Thursday she was aware of the "widespread concern" about the trial and was committed to working with advocates to address the issues.

Senator Hughes, who sits on the parliamentary committee examining independent assessments, has previously voiced concern about the Morrison government's plan to use contractors and a set of standardised tests to assess participants for funding.

But she's now intensified her criticism, suggesting in an interview with The Canberra Times the proposed change threatens to undermine the "choice and control" principal at the heart of the scheme.

Her comments echo the views of a broad coalition of opponents to the new model, which includes disability groups, academics, medical professionals, Labor, the Greens and most state governments.

The Canberra Times understands Senator Hughes voiced her concerns to colleagues in a party room meeting earlier this week, and has been privately lobbying senior Morrison government ministers.

Senator Hughes was particularly angered after new details emerged about how the results of assessments would be used to determine funding.

National Disability Insurance Agency chief executive Martin Hoffman last week revealed results would be fed into an algorithm with 400 "personas", which were based on different ages and disability types. That would produce a budget plan for the participant.

"I think it is dehumanising and offensive," Senator Hughes said.

"If you are someone without a disability nobody tries to box you, no one determines what you can do, how you fit, what your life should look like.

"This was the very ideal behind the NDIS - that people's lives would look like what they wanted them to look like. People's lives could best reflect what their families wanted their lives to look like.

"We are talking about people here - these are people's lives."

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Asked if she would feel comfortable having her 11-year-old son Fred put through an independent assessment in the form proposed, Senator Hughes said: "No."

She said some of her son's support workers had known him for almost a decade, meaning they had a deep understanding of his condition, progress and personal goals.

Senator Hughes said the new model did not account for a participant's goals and ambitions - a crucial feature of current system.

"They are very 'tick a box'," she said.

She "really, really hoped" Senator Reynolds would listen to the community's concerns, as she continues with a fresh round of consultation instigated by her decision to pause the permanent rollout of the new regime.

Senator Reynolds signalled she is open to making changes to the proposed model, but is adamant independent assessments will be introduced in "some form".

The new minister and Mr Hoffman have maintained the new system will result in more consistent decisions and improve fairness, with the government's decision to fund all assessments removing the potential cost barrier for low-income families.

Senator Hughes has left open the door to crossing the floor if changes aren't made before legislation is introduced to parliament.

"That's a bit hypothetical at the moment," she said.

"Certainly once there is legislation I will be having a very close look. In the Liberal party we do have the right to cross the floor.

"I'm a mum first and a senator second. My children will always come first.

"Yes, I have a role that I love and cherish and am so proud to represent and serve NSW. But my son is one of those people, as are 450,000, on the NDIS."

Elsewhere on Thursday, Disability Discrimination Commissioner Ben Gauntlett revealed during a Senate estimates hearing he had participated in the second trial of independent assessments.

Dr Gauntlett, who is a quadriplegic, described the process as "unsatisfactory" and said the model needed to be reviewed.

Responding to Dr Gauntlett's evidence, Senator Reynolds said she'd been aware of concerns about the trial since being appointed to the portfolio in late March.

She has committed to waiting for the trial to finish, and assessing its results, before any legislation is introduced to parliament.

Extending an olive branch to the sector, Senator Reynolds said she wanted to take a "more co-design" approach to help resolve the issues.

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