On arrival, he lashed mixed messages emanating from the Commonwealth, bemoaning he was “not confident” of a successful outcome.

Yet, before the meeting was even concluded he was already taking to social media to sing its praises:

Quick break in the Treasurers COAG meeting. Have to say one of the most productive meetings I've ever been in. Well done @ScottMorrisonMP

— Tom Koutsantonis MP (@TKoutsantonisMP) December 10, 2015

It was in stark contrast to his bolshy rhetoric just two hours earlier, when he warned of a “wasted afternoon” in response to public statements from Federal Treasurer Scott Morrison, who told the Financial Review overnight the Commonwealth could go it alone on tax reform with state deliberations “approaching a point of irreconcilable objectives”.

The Australian also reported Morrison wanted the meeting to progress competition reform proposals detailed in a report by economist Ian Harper – a suggestion that had Koutsantonis smarting.

“We’ve come here to talk about state and federal taxes, and how do we fund the gap in health and education… if all the Treasurer wants to talk about is Harper it’s been a wasted afternoon,” Koutsantonis told InDaily ahead of the meeting in Sydney.

“Quite frankly, until they’re able to tell us how we’re going to fund this fiscal gap with health – that they’ve created – it’s no good talking about Harper, or any other form of review on state-based taxation.”

He said the Weatherill Government and Mike Baird’s Liberal Government in New South Wales “have done a lot of work on the basis of conversations we’ve had with the Commonwealth Government on how to fund this fiscal gap they’ve created”.

“They told us: ‘Go away and think about a solution’, so we do … we come back to them with a solution, and now all they want to talk about is Harper,” he said.

Sydney’s Daily Telegraph today reported that Baird was set to introduce its own Emergency Services Property Levy, averaging $160-a-year per household.

The Treasurer’s meeting, and the tone struck, will foreshadow tomorrow’s COAG conference, which Premier Jay Weatherill has today jetted in to Sydney from Paris to attend.

Koutsantonis said he was “hoping today we’d have a much deeper discussion” about broad tax reform, warning: “I’m not going to take SA from the lowest taxing state to the highest, just because Scott Morrison doesn’t fund health properly – that’s not going to happen, that argument is off the table.”

“If he wants to have an honest discussion, I’m prepared to cut taxes, I’m prepared to remove inefficient taxes…but if it’s just ‘I can’t give you any extra money’, I’m not going to come back to SA and tell our community ‘Scott Morrison won’t give us a dollar extra so I’ve got to increase land taxes, stamp duties and business taxes’.”

Weatherill has flagged a model whereby the GST will rise to 15 per cent, with the Commonwealth collecting the extra revenue, and state revenue increased by a greater share of income tax receipts to cover the health gap.

Despite the Abbott Government maintaining there would be no change to the GST without state consensus, Koutsantonis maintains “it can be amended by the Commonwealth Government whenever it wants”.

“It’s not a constitutional amendment, it’s an act of parliament, and parliament can change it any time it wants,” he said.

“The fiscal gap has to be dealt with (and) I don’t think the GST can fix it … the GST is not enough to fill the funding gap – it doesn’t raise enough money.

“The state has got an unemployment level that’s unacceptably high … I’m not going to allow Scott Morrison to bully us into increasing our taxes to pay for his health cuts.”

However his subsequent tone suggests the meeting has been more ebullient than bullying.