The next step will be a binding agreement - the long-awaited South East Queensland City Deal - to be signed in mid-2020 regardless of the May 2019 federal election outcome.

It's claimed the region's economy could expand by $58 billion by 2041 under the wide-ranging agreement, factoring in just a 0.25 per cent boost to efficiency.

Under the plan, about 800,000 new homes will be built for the 1.9 million new residents in the region, ostensibly without sending koalas extinct or constricting green space.

It will identify new creative precincts, sports precincts and travel links.

Queensland Treasurer Jackie Trad breathed a little easier after signing the documents with Cities Minister Alan Tudge and Brisbane lord mayor Graham Quirk.

"Fundamentally I now think this is going to go ahead," Ms Trad told 550 delegates to a Queensland Property Council lunch after the signing.

Cr Quirk - also the chairman of the South East Queensland Council of Mayors, which lobbies on behalf of nine south-east Queensland councils - said it was time to move away from political infighting.

The short, three-page document signed on Friday was a statement of intent for a future South East Queensland City Deal, Australia's ninth and likely to be its largest.

Since December 2016, City Deals have been signed or mooted in Darwin, Launceston, Townsville, Western Sydney, Adelaide, Hobart, Geelong and Perth.

"We know that south-east Queensland is one of the fast-growing areas of Australia," Mr Tudge said on Friday.

"And we need to make sure that the three levels of government are working cooperatively together to ensure that we can maintain the pace of growth, while ensuring that we maintain the liveability at the same time."

"This will be the largest, and most complex, City Deal 1that we will negotiate across Australia."

The statement followed a mixed record of intergovernmental cooperation to build big projects.

The extension of the Gold Coast light rail project to the heavy rail link at Helensvale in time for the 2018 Commonwealth Games showcased three levels of government chipping in to produce a significant result in a tight timeframe.

But discussions about Brisbane's various Cross River Rail projects have constituted an ugly, 12-year political sore on the relationships between consecutive Queensland and federal governments.

The Queensland government eventually decided to build the underground rail link alone.

Cross River Rail and the council's Brisbane Metro bi-articulated bus network project, as well as the Commonwealth's Inland Rail, are covered under connecting infrastructure.

Jobs and skills, liveability, housing, building a new digital economy and building upon tri-governmental leadership comprised the other five sections.

Ms Trad said the city deal had to be regional because of south-east Queensland's connectivity, with people commuting from the Redlands and the coasts for work and services in Brisbane.

"This the fundamental characteristic of our population here in south-east Queensland," she said.

"Unless we understand that - in terms of pressing the City Deal - then it will be a failure."

Cr Quirk emphasised the region's power.

"You go to a local government in any other part of this country and they do not have the collective respect that the South East Queensland Council of Mayors has," he said.

"When we go to Canberra, we go with one voice. We go with a combined hymn sheet if you like, where we have agreed on the agenda as to where we are going to go regardless of political differences."

City Deals build on large transport infrastructure projects - like Cross River Rail, the Gold Coast light rail project and the future Sunshine Coast light rail project - and open up land for housing, community infrastructure and businesses.

The City Deal needs to be nutted out over the next 12 months, when politicians will consult on project definitions and priorities.

It will ultimately be signed in mid-2020.

Mr Tudge said he could not yet estimate the financial scale of the deal.

"I think all three levels of government are going into this with good intents to work through the process," he said.

He did not accept that federal Labor's promise of $2.24 billion to Cross River Rail - which the Coalition would not match because it wants to put its money elsewhere - was an indicator of how much it might put towards the SEQ City Deal.

"It is just impossible to say at this stage what the scale of the (City) Deal is, or what it is going to look like."

Federal Labor backs the concept and - if it wins the federal election in May 2019 - will support any deal that has been signed.

Mr Tudge on Friday said he regarded the federal, state and SEQ Council of Mayor's as being in "equal partnership" in a SEQ City Deal, similar to Labor's position of giving councils more say.

Shadow Minister for Cities Anthony Albanese questioned the timing of Friday's announcement.

"The Coalition has had six years to sign a City Deal with south-east Queensland and, just like its other City Deals, it’s taken an election to get them across the line," Mr Albanese said.

"In this time they have dudded the people of south-east Queensland by not investing a single dollar in the project that would make the biggest difference in the region – Cross River Rail.

"We will overhaul their politicised City Deals program and replace it with City Partnerships, which will involve genuine collaboration with state governments, local councils and their communities."