The council expects to appear in the High Court in two or three months' time to respond to the challenge from Fish & Game and Forest & Bird to the board of inquiry decision.
"[His submission to the board] quite clearly represents a conflict of interest should Councillor Belford also wish to vote on HBRC's position on Plan Change 6," Mr Wilson told Wednesday's meeting.
"Should Councillor Belford not acknowledge his conflict on Plan Change 6, as a submitter to the process, then this quite clearly presents a challenge for council.
"As chairman, and knowing this, I can't let it ride. I have to take this further. It exposes council to the risk of judicial review in any of its decisions on Plan Change 6."
He said if Mr Belford did not declare an interest, and withdraw from voting, he would "place Hawke's Bay regional ratepayers at the risk of having to fund judicial reviews of any decision made by HBRC from now on, on Plan Change 6".
Mr Belford told the meeting he was "outraged" Mr Wilson had not discussed the matter with him beforehand.
"I think that is an abominable abuse of process in your regard, so I'm just taking this in for the first time here. I have maintained I am not predetermined on any aspect of this matter, whether it's Plan Change 6 or the dam."
Yesterday Mr Wilson told Hawke's Bay Today the risk of the council facing a judicial review over the issue related to Mr Belford was "probably low".
"It's a very low risk. Even so, there's still a risk there and it was my duty as chairman to point it out," he said.
"In all these issues, if there is some doubt there, and there is some perception of conflict out there in the community, the common sense thing to do is stand down, but Tom's done his homework and he's said no, he's going to carry on and that's fine."
Asked why he didn't discuss the matter with Mr Belford before Wednesday's meeting, Mr Wilson said: "I discussed it with him afterwards and said why would I give you a heads up, Tom, on the basis that you weren't going to shift your position.
"We had quite an amicable chat afterwards. There's no personality stuff there."
Mr Belford said the issue had been raised by a number of councillors over several months.
"They regard me as the most dangerous sceptic about this whole [Ruataniwha dam] proposition so they've painted a bulls-eye on my back and they'll be at it, I'm sure, until the cement has dried on the dam, if that's the way it proceeds."