He said the challenge was that, as the functions of regional councils were so different to those of the territorial councils, unitaries around the country struggled to deal with the issues of the primary industries.
"Functions of the regional council are too important to water down in a unitary," he said.
"And the region is run on primary industries, simple as that.
"I haven't had any assurance from anyone and there is not enough detail to convince me I am wrong.
"So I am left with very little alternative but to vote against it."
Asked if amalgamation did go ahead what the new structure of governance would look like, he said: "A big ugly brute of a thing, that is what it will look like."
The chairman struggled to vocalise any benefits of such a structure.
"The bit that everyone is forgetting, and it [has been] forgotten right through the last two years, is we already have a regional council," Mr Wilson said.
"So I get my head around that, I can understand that bit. But any other benefits are pretty hard to quantify when you add every single component of local government together, when the two different entities are so different."
If amalgamation did not go ahead on September 15, Mr Wilson said, the region had to do better.
"I think there is a lot of dissatisfied people out there.
"We have got to take notice of this as a region," he said.
"You can call it politics and whatever, and unfortunately it has degenerated into that.
"But we have got to do something better as a region, going forward."
He said he would be interested to hear from people what the real issues were that affected them, if amalgamation did not go ahead ... "not a wishy-washy wish list of more fish in the Bay and stuff, but what are the key drivers here.
"Is it the planning process? What are the real issues?
"Because those issues are not going away if this doesn't go ahead. I don't think we have ever addressed the real issues of Hawke's Bay of local government.
"We do our thing individually. I think the councils generally perform really well.
"We need to be pretty clear on what we are dealing with, what has driven this level of dissatisfaction to generate this whole great big process."
Mr Wilson concluded that, whatever happens, he is prepared with all his colleagues at the HBRC to roll their sleeves up and "do the regional thing and do it well".
"At the end of all this, whichever way it goes, there is going to be some bruised people out there," he said.
"I think the biggest risk is that, if it doesn't work, trying to get all the relationships back together again when they are so fractured at the moment.
"I see a role probably for the existing regional body and I want you to stress that, because we have already got a regional council.
"It is just called Hawke's Bay Regional Council, not Hawke's Bay Council.
"It already exists.
"So it is going to take a lot of effort from all of us to actually get this thing back on track, no matter what the outcome is.
"And I am prepared with all my colleagues at the regional council to roll our sleeves up and do the regional thing, and do it well."
