Yesterday the Otago Chamber of Commerce voted to go forward with the merger, 68% of members in favour of the proposal.
The employers association’s vote for it last week means the "Business South" merger need only be confirmed in two meetings being held later this month.
But the attempt to amalgamate has drawn the ire of both the the Southland Chamber of Commerce (SCC) and Southland’s economic development agency, Great South.
The chamber said the merger would encroach on its area and the name Business South would confuse its membership.
Chamber president Neil McAra said it was disappointing there had not been wide or meaningful engagement around the merger process, given it would affect some Southland members.
"We’re opposed to their use of the name ‘Business South’ because it masquerades as having Southland businesses’ interest at heart, when we feel this is not the case, and will confuse the market."
Southland chamber chief executive Sheree Carey said the Otago Southland Employers’ Association (OSEA) vote approving the merger last week took place in Dunedin and did not offer an online option for members in Southland.
“How does that fairly represent everyone’s interests when their Southland members don’t get a say unless they physically drive to their Dunedin head office?”
Great South opposed use of the name Business South as it was concerned it would confuse people and businesses not only locally but also at a national level.
"Great South has a clear mandate, and significant national body and government support, to deliver business development services to businesses in Southland," Great South chief executive Graham Budd said.
In response to the criticism of the merger OSEA president Andrew Leys said successful mergers of chambers of commerce and employers associations in other areas proved it was a good move.
"This has been shown to be the case in both Canterbury and the lower North Island," he said.
"In both instances the merged organisations continue to collaborate with and support independent chambers still operating within their geographic region."
He was asked if another name could be considered to avoid confusion, but he stood by Business South.
"The proposed name Business South for the organisation expresses the fact that it will represent the common interests of business in the lower South Island, including Southland, as the OSEA has proudly done for close to 130 years."
Mr Leys reiterated his support of the Southland chamber, of which he has been president in the past.
"I would not be a party to anything that is detrimental to the local chambers in Southland or Otago," he said.
"Any suggestion that the proposed new organisation would seek to undermine the great work and role of the SCC — or any other local chamber — is unfounded."
Otago Chamber of Commerce chief executive Grant McKenzie did not want to comment on whether Business South would confuse members of other chambers.
"We have engaged with the president and board of the Southland Chamber of Commerce and the other Chambers of commerce in our region," he said.
