About 170,000 hectares is mooted to accommodate 14,000 troops a year arriving from Singapore. Most of land on the slab makes up some of the country’s best, drought-resistant grazing property, home to 100,000 head of cattle. There is a further 5,000-plus hectares of national parks and state forest.

The Australian government, which engaged KPMG to carry out a socioeconomic study of the plan’s impact, has fast-tracked the release of the exact properties the Department of Defence is eyeing to next month.

Up to 50 cattle property owners are believed to be in no mood to hand over their land titles without a fight. The political salvos fired on their behalf have come from some of the federal government’s familiar antagonists – the Queensland state government and the federal Labor opposition as well as Pauline Hanson’s One Nation.

But then, on Monday, the Queensland Liberal National party opposition joined the chorus of complaint. The LNP leader, Tim Nicholls, said he had written to Prime Minister Malcolm Turnbull asking that he “immediately intervene”, suggesting the Australian Defence Force had botched its handling of a plan that left rural landholders in limbo and failed to persuade the community that forced acquisitions were necessary.

“The [Australian Defence Force] has dropped the ball on this and hasn’t clearly communicated the process to the potentially affected landholders or successfully justified the acquisitions to the wider community,” Nicholls said.

Under the new defence deal, the Singapore military would triple its annual access to the Australian training grounds to 18 weeks. Singapore troop numbers will increase from 6,600 to 14,000.

Singapore and Australia would jointly develop the two training areas, with the city state

spending up to A$2.25 billion (US$1.7 billion) to double the capacity of its facilities.

Vying for the decisive contribution to a growing controversy, Hanson on Tuesday said she understood the proposed forced resumptions “may well breach” the Land Acquisition Act that empowered the Department of Defence to take over properties, as well as the constitution.

She questioned whether the need to accommodate Singaporean troops as part of a training deal under a free trade agreement met “the ‘public purpose’ as required by the legislation”.

“There is no public support in this acquisition, nor is there any purpose behind it,” she said.

“The army has stated the public will benefit from this acquisition; however no benefit can be demonstrated.”

She added: “If the farmers affected by this land grab were to take the matter to the high court they would have a very arguable case that they might very likely win.”

The federal opposition’s spokesman for agriculture, Joel Fitzgibbon, was dismissive about the utility of a high-court challenge to the community at this point.

“Legal action should be a last line of defence and, if it ends up there, landholders and local businesses will be living with years of uncertainty,” he said.

But some willing sellers have already emerged. Glenprairie cattle station – whose owners have ranged from a knight to a Greek shipping magnate and the family of Australia’s first billionaire, Robert Holmes a Court – sold this month for as much as $45 million, the Australian Financial Review has reported. .

But scores of families who have spent generations running cattle on land largely immune to drought are loath to start again elsewhere.

A protest rally for farmers is due to be held at the Lakes Creek Hotel, north of Rockhampton, on Wednesday evening.