Hamilton's mayor says he's been told if council's don't endorse an amalgamation proposal they will not be at the table for reforms.

In May, the government gave councils three months to come up with a Head Start proposal for merging into larger unitary councils.

The Head Start process was voluntary, but if council's did not participate, the government said it would step in to ensure reform still happened through a backstop process. That process had not yet been finalised.

But despite this, Hamilton City Council today decided, with 12 votes in favour and three against, that it did not want to submit a Head Start proposal.

Mayor Tim Macindoe said he had a phone call with Local Government Minister Simon Watts on Wednesday night, where Watts stressed that opting in with a Head Start proposal was just stage one of a process that would enable council's to keep developing models over the months ahead.

"However, he was also quite clear during our discussion that backstop council's will not be at the table for that process.

"His messages were fairly clear, his tone was pleasant throughout, it wasn't threatening, but it didn't leave me with hope we could still be at the table to negotiate if we are a backstop council."

Councils that take part, he was told, were likely to be at the forefront of stage two of regional and city deals that will be considered in the near future.

Macindoe said as the fourth largest city and fastest growing, he would push to be involved in the reforms regardless of its decision today.

"I did express the view that I would expect to be able to be a part of discussions no matter what the outcome of today's decision would be and I still think its inconceivable that we wouldn't be.

"How could we possibly be in a position where other council's are making decisions that have a profound impact on the future direction of New Zealand's fastest growing and fourth largest city."

He said following the vote, they would either be at the table or "have to push that very, very firmly".