Kaimai is calling now that Tauranga's Eastern Link is complete.

The Kaimai connection - completing the golden triangle between Waikato and the Bay of Plenty - is being discussed at the highest levels.

On Friday, Transport Minister Simon Bridges said he is encouraged by the idea.

"It is pretty hard to argue against, at least in principle, the idea of carrying it on to some degree to the Bay of Plenty," said Bridges. "It is a very compelling idea to continue."

ALEXANDRA NELSON/FAIRFAX NZ Transport Minister Simon Bridges finds a Kaimai connection compelling.

Early in January, Hamilton City Councillor Martin Gallagher and National MP for Taupo Louise Upston called for an expressway between Hamilton and Tauranga to be prioritised.

READ MORE: Tauranga port link priority for expressway

"Of course, I'm not digging myself into any election promises at this stage, because there is a whole lot of planning and investment required," Bridges said.

PETER DRURY / FAIRFAX NZ Time to talk the Kaimai connection.

National's Hamilton East MP, David Bennett agreed it is time to turn concept into reality.

"The next phase for the Waikato is to connect with the Bay of Plenty," said Bennett. "We have an existing connection, but it certainly can be improved."

Tauranga Mayor Stuart Crosby agreed his city's priority is the connection to Auckland through the Waikato.

FAIRFAX NZ Labour transport spokeswoman Sue Moroney.

"That golden triangle is real," said Crosby. "We've been part of the Upper North Island Strategic Alliance and there has been good work done on that."

Tauranga's $455 million roading project, the 23-kilometre Eastern Link between Te Maunga and Paengaroa was completed last year, opening land to the east for development.

Tauranga is ready for the next step, said Bennett, and by 2020, the Hamilton and Huntly sections of the Waikato Expressway would be complete.

"If we can join those two desires together and create a joint approach, where both regions are seeking the same thing, that gives us a lot more power to negotiate and seek that opportunity in Wellington."

The Kaimai Range is the obvious hurdle and Bennett didn't foresee any radical solutions.

Hamilton Mayor Julie Hardaker said a tunnel would solve the problem, but would be costly.

"That's always been a major issue because that would require tunnelling and that's certainly an expensive item," said Hardaker.

Regional leaders on both sides of the divide took a collaborative approach to regional infrastructure as part of the Upper North Island Strategic Alliance, but a formal discussion on an expressway link is yet to take place.

"There hasn't to date been any formal, cross-boundary discussion with the Bay of Plenty about where to from here with the Waikato Expressway," said Hardaker.

While the Tauranga link is vital, Hamilton's priority is on the Southern Links project to connect West Hamilton with the Waikato Expressway, regularly referred to as the Peacockes Road link.

"It's an opportunity to open up the industrial area around the back of that western side of the city."

Hamilton is seen as the main logistics hub for the upper North Island while Tauranga has the port.

Tauranga's population is projected to reach nearly a quarter of a million by 2065 while Hamilton's is expected to reach 210,000.

Hamilton List MP and Labour's transport spokeswoman, Sue Moroney said that invited competition for government services.

"One of the reasons why we are in that competition with Tauranga is because we are not effective enough in terms of [Parliamentary] leadership in the city," said Moroney.

Last July, Waikato University planted roots with plans for a $40m Tauranga campus funded largely by the Tauranga community aimed at keeping young people in the Bay of Plenty.

In April, a decision would be made on the future of Hamilton's Inland Revenue building - stay in the CBD or shift to a new site outside it.

Throw Tauranga into the mix and the fight could be to keep the department in Waikato at all.

"Initially it is about securing it in the city," said Moroney.

"If we get these decision wrong within Hamilton and we don't get those central government services hubbing together in the best location for that, eventually there will be questions asked about whether Hamilton is the right place for them or not."

Crosby preferred to see new services distributed through a regional approach.

Key services would be health, transport and education.

"With regionalisation goes delegation to make decisions and that speeds things up the process," he said.

"And so other departments, particularly education, could do well with that model and make some strategic changes."