The former chairman of the state government's Hunter Development Corporation (HDC) says the organisation had a pact with the community not to develop Newcastle's heavy rail corridor.

After seven years in the job, Paul Broad resigned last week, effective immediately, citing "a massive shift in power from Newcastle to Macquarie Street".

He says the Hunter lacks a unified position on issues, such as the heavy rail line, and the region is "losing its voice".

Mr Broad said the government should tell its development arm, UrbanGrowth NSW, that it cannot develop the rail corridor.

"When we, HDC, were putting the renewal report together we sort of had a pact with the community that we wouldn't be developing the corridor," he said.

"I think there is still an enormous amount of land still to be developed around Honeysuckle, and other places, so I was always a bit surprised when it was proposed to UrbanGrowth to do that development.

"It just was not part of what we originally intended."

UrbanGrowth is currently in the middle of a six-week consultation on what the community wants done with the heavy rail corridor.

Mr Broad said it should not be developed.

"As someone who has fought for the last part of my professional life to keep corridors, you never give a corridor away.

"There's no better example than that when you look at the Sydney basin, and the M4.

"There was a corridor connecting the M4 to the city.

"Neville Wran sold that and now, to get the city reconnected, the fact that we have to then dig underground to do it, is just massively costly and massively disruptive."