It could also have ramifications for Sydney councils challenging proposed mergers in the courts.

But it will not affect Dubbo Regional Council.

Ku-ring-gai Council this week won in the Court of Appeal on five of its six arguments mounted against the process used to justify a proposed merger with Hornsby.

At the heart of its challenge was a report by consultancy KPMG, which recommended council mergers and which the government refused to release in its entirety, claiming it was subject to “public interest immunity”.

Judges Robert Macfarlan and John Basten ruled the delegate appointed to assess the proposed merger could not have properly carried out his assessment without access to the KPMG report.

“It sounds like the judges were reading my mind,” Mr Dickerson said.

“I was certainly very vocal at the time, saying ‘how can we be basing any of our information on a report that’s hidden?’ We didn’t support it and part of the reason was we had no evidence that this was a good idea.”

Mr Dickerson said the fact Dubbo MP Troy Grant was no longer deputy premier, Mike Baird was no longer premier and Paul Toole was no longer local government minister indicated the government’s mergers policy “wasn’t a very sensible or smart way to go”.

“But I don’t really get too excited about saying ‘yes, we were right’ … nothing has changed,” he said.

Mr Grant said the region’s towns and villages were “working together like never before”, after years of neglect under Labor governments.

“We … have a local government structure that will see us become a regional economic powerhouse … I urge all candidates considering running [in September council elections] to put the future of our community first,” Mr Grant said.