In an extraordinary admission as he gave evidence in person to the Electoral Districts Boundaries Commission in the federal court this morning, the Trade Minister – who gained his ministry when he quit the Liberal frontbench to bolster the Weatherill Government’s tenuous majority – said if he was re-elected and held the balance of power after 2018 “I’m big enough to do what’s in the best interests of South Australia”.

“I’d have no doubt if it was up to my vote, I’d be courted by both the Liberal Party and the Labor Party – and all would be forgiven,” he said.

“And I’m open to forming a Government with either the Liberal Party or the Labor Party.”

The admission, however, earned a swift and firm response from Opposition Leader Steven Marshall, who told InDaily the one-time party leader would “never, under no circumstances” rejoin a Liberal cabinet.

But Hamilton-Smith insisted that “if either party were to offer me an opportunity to continue serving the people of SA in cabinet, of course I’d consider it”.

“Any MP who didn’t would have to ask themselves why they’re there [and] I’d be happy to consider such an offer from either a Liberal or Labor government,” he said.

Indeed, he continued, it would be “easier for me to support the Liberal Party”, given “my political values remain unchanged – I stand for the same core values that would align with the Liberal Party”.

“The Liberal Party holds no exclusive claim or purchase on the values of Liberalism,” he said.

“I’m very aware my seat [the inner southern suburbs seat of Waite] is principally a conservative seat… the people of Waite voted for someone with Liberal conservative views and they still have one.

“The difference is I’m in Government – every other Liberal conservative MP is in Opposition.”

He said ultimately “I’ll make that decision after polling day” based on the quality of the respective parties’ policies, primary vote outcomes in both Waite and the broader community and “which of the two parties will deliver stable Government to the state”.

The general feeling was we did a sterling job, ran a great campaign and the only reason we lost was the boundaries

As InDaily revealed last month, Hamilton-Smith requested to address the boundaries commission, chaired by Supreme Court judge Ann Vanstone, to argue against a wholesale boundary redistribution, insisting successive Liberal losses despite a statewide majority of the vote were own-goals predicated on a raft of internal flaws, in particular a perpetual focus on “a low-volume, small-target strategy”.

He revealed he “got an urgent phone call roughly two weeks from election day [in 2014] from the leadership”, who he said told him: “We realise now we’ve got no policies – can you give us 10 bold ideas we can take?”

“I did that, and it was ignored, but there was a panic towards the end that we hadn’t been bold enough,” Hamilton-Smith told the commission.

“There was a sense we could buy the election by filling people’s letterboxes with propaganda [but] we had the emphasis in the wrong places.”

He highlighted announcements he claimed played to “older safe-seat rural voters in the final days of the campaign”, including an irrigation system in Goyder, an infrastructure grant for a racetrack in Hammond, a motorsport park in Tailem Bend and $300,000 additional funding for the SA Jockey Club.

He also lamented a lack of female candidates and “first or second generation cultural representatives” – that’s despite Labor infamously targeting the Liberals’ Lebanese-descended candidate Carolyn Habib in Elder.

“I think the Liberal Party’s fallen into the trap – and I fought against this for years – of focusing on rural seats or safe seats within Adelaide,” Hamilton-Smith told the commission.

He also highlighted the “Wok In A Box issue” – wherein questions were raised about Steven Marshall’s former business franchise – and “a number of problems in the campaign”.

“The commission has been blamed if you like, certainly within the Liberal Party after each election, for election losses… I’ve always held a view that that accusation has been unfair,” he said.

After 2010, when Isobel Redmond’s Liberals won almost 52 per cent of the vote but fell well short of a parliamentary majority, Hamilton-Smith recalled “the general feeling was we did a sterling job, ran a great campaign and the only reason we lost was the boundaries”.

“If you put the effort into safe seats that you already hold and don’t put the effort towards the marginal seats that you don’t hold, you can only hold yourself responsible for the outcome,” he said.

“The challenge in our constitution is for the team that wants to win that election to broaden its appeal so it not only wins the majority of the vote but a majority of the seats.”

He said his former party “can’t agree on a party platform” because “the moderate division and conservative division have quite opposing philosophical viewpoints”.

“Apart from a few documents that loosely talk about what we believe, there’s little in the party platform that gives people in marginal seats a firm idea of what we stand for,” he said.

He said the strategy was always about “waiting for the Government to lose the election, rather than get out there with a bold alternative”.

“The party’s fallen into the trap of waiting for the Government to lose, but the Government hasn’t lost for a long time,” he said.

“It might work when you have a Government in freefall, but when you have a Government that’s solid you need to be a little more creative than that.”

Hamilton-Smith spent considerable time defending his decision to join the Labor frontbench, saying a firmer majority “meant the Government could be bolder and braver and be more stable”.

“The only way a Liberal voice was to be heard in Government was this way,” he said.