Wairoa Mayor Craig Little told Hawke's Bay Today he was "very, very concerned" Mr Wilson was not included, as it meant their district was not represented.
"The problem is [the six councillors] are coming to the meeting fully informed, they've probably made their pre-determinations beforehand and so he [Mr Wilson] is on the back foot straight away."
Last week council chairman Rex Graham said he and the other five councillors did meet to discuss issues, but never to reach a consensus, and never to pre-determine their votes.
Mr Little said he could not think of any recent examples of when Wairoa might have been affected by Mr Wilson's exclusion, but added: "Wairoa always feels like we're the last ones off the rank, anyway, for any decisions made down that way".
"This is just another example of basically how insignificant we are around their table if they don't want to include our councillor."
He had no problem with the "pre-meetings" occurring, but felt all councillors needed to be included.
His sentiment was shared by Central Hawke's Bay Mayor Alex Walker, who said it was concerning if the six were discussing strategies they would be taking to council meetings.
"We rely on the fact that all members are elected to represent the whole region and the purpose of our member who represents us, is to take our perspective to the table," she said.
"So when there's decisions being made and strategies being worked out it's important that all members are there.
"If everybody's not represented it's difficult to say they're representing the whole of the region."
When asked if she was concerned the six were the councillors not in total favour of the Ruataniwha Water Storage Scheme, which would be located in Central Hawke's Bay, she said she was.
However, Ms Walker added this would "absolutely depend" on what the councillors had discussed about it, which was not known.
In response to the mayors' concerns, yesterday Mr Graham said he thought the two districts were being "much better represented than they were in the past" citing this council's focus on boosting Wairoa's economic development.
"I think their representation and the focus on the wider region has been much more intense with this new council than it was with the last council," he said.
"I would think our council is highly motivated to do the best it can for the whole region."
The third councillor excluded from the meetings is Napier councillor Alan Dick, whose two fellow Napier councillors are included.