Cr David Benson-Pope has submitted a notice of motion, seeking support from councillors to scrap plans for an in-house investigation of the merits of the DCC merging with the Otago Regional Council.
The motion will be considered at next week's full council meeting, to be held on Tuesday.
The move potentially puts him at loggerheads with Cr Lee Vandervis, who, in 2017, won support from other councillors for the idea.
The debate that year had begun with talk of supporting community boards in a joint approach with the ORC to issues they all faced, but escalated as Cr Vandervis suggested the idea of a unitary authority.
Raising the idea - one he had been promoting for years - prompted Cr Benson-Pope to challenge Cr Vandervis at the time to ''stop bleating'' and put forward a motion.
Cr Vandervis obliged, seeking a high-level report on the advantages and disadvantages of becoming a unitary council, and the process to follow.
Councillors voted unanimously in favour of the motion, including Cr Benson-Pope, who seconded it.
However, more than two years on, work on the report is yet to begin and the Otago Daily Times understands grumpy emails have been circulating as a consequence.
Cr Benson-Pope, contacted yesterday, said the report had not proceeded ''for reasons of work priority, which the chief executive has explained to us''.
He wanted to reverse the earlier resolution ''because I don't think proceeding in that direction is appropriate at this time''.
Despite that, he predicted a ''sideshow'' at next week's meeting.
''I think it will be widely supported by the vast majority of the council, but ... it's election year and we've got lots of mayoral candidates, haven't we?''
Cr Vandervis, who is seeking another council term but yet to announce whether he will also try again for the mayoralty, did not respond to requests for comment yesterday.
