Kevin Jeffery and Michael Lonergan, who sat on the council for more than four decades combined, say they've never seen an intervention to rival Ms Whelan telling current chair Dr Sarah Ryan that she had lost confidence in the group's expert advice.

Ms Whelan had accused some council members of undermining her agency by criticising the government's external review of the fire season, which they believed had overlooked key problems raised by volunteer firefighters.

"Comments from council members discrediting this significant piece of work are extremely disappointing and concerning," Ms Whelan wrote in the September 22 letter obtained by The Canberra Times.

The commissioner has since insisted that she does trust the council's advice, but that she wants its feedback to be communicated in a more "constructive" way.

Dr Ryan has chosen not to publicly respond to Ms Whelan's letter despite requests from The Canberra Times.

But Mr Jeffery and Mr Lonergan have chosen to speak out, angered at what they consider an alarming intervention into the independence of the expert panel.

Mr Jeffery, who chaired ACT Bushfire Council for a decade, said Ms Whelan appeared to have a "low tolerance for advice".

He said a natural tension had always existed between council members and the commissioner and minister of the day, because bushfire management was an inherently complex and contentious topic.

"The advisory body is almost always going to present advice which you aren't comfortable with ... that should be acceptable, that isn't bad," he said.

"The more complex an issue is, the more you need advisory mechanisms. You can't possibly have all the knowledge.

"[Ms Whelan's] letter reads as though someone who does not want to listen."

Mr Jeffery - whose father Val also served on the bushfire council - was concerned Ms Whelan's "reprimand" could make some members afraid to speak honestly.

Among the members of the 12-person council, who are appointed by the emergency services minister, are experts in the fields of firefighting, fire science and land management.

"The council needs to allow the conversation to occur, it needs to allow a bit of digging. You can't get too defensive," he said.

"I do hope that the council continues ... and continues at arm's length. It's a complex space and it needs to exist."

Mr Lonergan, who served on the bushfire council from 1988 to 2016 and was a member of the ACT and NSW rural fire services for almost 40 years, described Ms Whelan's letter as "demeaning".

He believed there had been a steady decline in the level of technical expertise on forestry and fire management within the agency and council, which meant feedback from people with knowledge in those fields was all the more important.

"If those views are discounted then you are courting disaster," he said.

"Val Jeffery used to say that cities have floods and earthquakes, well Canberra has fires as it major emergencies. We need to understand them better than we do at the moment."

In an interview with The Canberra Times last week, Ms Whelan said the agency and the council had a "robust and healthy relationship".

She said the council put forward views and recommendations which she didn't always agree with, but indicated that was expected in what she described as an "environment of contestability".

However, she remained critical of how council members communicated their views.

"There are times where the way in which some of that information or opinions are relayed, I would like to be a little bit more constructive," she said.

Emergency Services Minister Mick Gentleman this week said he trusted the council's advice and had no plans to sack any of its members, which he has the power to do under the ACT's Emergencies Act.

"I recognise that while views on bushfire management may differ, both the ESA and the Bushfire Council are committed to keeping Canberrans safe," he said.