Early last month, Minister for Housing, Planning, Community and Local Government Simon Coveney said that the report of the committee he established last year would be ready for publication within two weeks, but it still hasn't been delivered.
The report is reviewing previous recommendations to dissolve both councils and create one 'super council' that will govern the entire city and county, with an expanded metropolitan district replacing the current city authority and boundary.
Mr Cahill said that if the metropolitan area is expanded and included as a part of a merged council, then for the next two election cycles, the current members of Cork County Council would be included with city councillors in the metropolitan body. He predicted that county councillors would more than likely side more with their former county council colleagues, creating friction in the metropolitan district.
"That's a big fear of mine. That's not to say that it would be intentional. It would be a natural reaction. But the consequence of that would be negative for the metropolitan region," he said, warning that the city, rather than driving the region, could be stripped of cash by the county instead.
Mayor of Cork County and Fianna Fáil councillor Seamus McGrath said that he appreciated that there had been no leaks on the report so far and that the process was fair, and that Cork County Council is waiting to examine and respond to it.
"This is a waiting period. We have no idea what the outcome will be. There are no leaks, so everyone will see it at the same time. That's fair to everybody," he said.
He said that the County Council had engaged with the group and followed up on information that was requested, and would be ready to fight their corner when the report was published.
Mr Cahill said that the City Council was in the same situation, and that its position had not changed since the last report, delivered in 2015, when they opposed a merger while the County Council supported one.