The incident involved an email sent by the mayor which talked about an investigation into a combined Three Waters entity for Otago and Southland.
Campbell said his position was well-known that he opposed the idea of a combined entity with the other region because of how large it would be.
“I think Invercargill will suffer from being too far away from the centre," he said.
"My view is that we need a Southland entity.”
The incident was cleared up within a few hours once Campbell realised he had misunderstood Clark.
“I replied to him that I thought that if he was going to pursue that, then it was inappropriate for me to be deputy mayor because he knew that I opposed it.
“He sent me an email back saying ‘No, look you’ve misunderstood, basically. It’s only an investigation that I’m doing’.”
Campbell said the mayor told him the option of a stand-alone Southland entity was also being investigated.
He said there must be a “mole” in the council who was sharing what was happening.
Local Democracy Reporting approached Clark but was told he did not wish to comment further.
He said he would oppose a scheme where Invercargill might be asked to sacrifice for "the greater regional good".
Under the previous Labour government's plans, the Affordable Water Reforms - earlier called Three Waters - would have created new water entities responsible for water assets.
The coalition government repealed those water reforms in February this year and is developing new water reform policy called Local Water Done Well.
An advisory board will work on replacement legislation, which would allow neighbouring councils to voluntarily band together to form council-controlled organisations.
- By Matthew Rosenberg
Local Democracy reporter
LDR is local body journalism co-funded by RNZ and NZ On Air
