The federal government spent more than $275,000 in legal costs last financial year on challenging requests for urgent medical transfers of asylum seekers and refugees on Nauru and Manus Island.

The cost is likely to be far higher this year, with a growing number of critically ill people seeking the federal court’s intervention after officials refuse recommendations from doctors to bring them to Australia.

In many cases doctors have repeatedly recommended transfers for patient, sometimes for months or years, only for the recommendations to go unheeded by governing authorities, including both the Australian and Nauruan governments, until a federal court order for a medical transfer can be obtained.

In responding to questions on notice to the Senate last month, the department of home affairs revealed it had incurred $326,012 in legal costs in responding to those court proceedings. In October, this was corrected to $275,00 in Senate estimates.

The amount is not believed to include the costs of the urgent transfers themselves, including air ambulances and subsequent treatment for critically ill patients.

The Department of Home Affairs and the office of minister Peter Dutton did not respond to questions.

“This is a shocking waste of money, but even if it was free, it is unconscionable to prevent children from getting medical care,” said Greens senator and immigration spokesman, Nick McKim.

“There can be no excuse for keeping any human being in these conditions.”

It does not appear any transfer applications to the court have been dismissed, and many more are expected to be lodged amid a worsening physical and mental health crisis on the island.

So far in 2018 one of the legal groups involved, the National Justice Project, has had 22 legal matters, with 19 involving children as the primary applicant.

Guardian Australia is aware of at least 10 cases run by other firms.

Ten of the National Justice Project’s cases (including nine involving children) had court proceedings filed, and a total of 73 people, including 31 kids, have been brought to Australia.

Many are critically ill, with several cases of resignation syndrome – a rare and potentially fatal condition which develops as a reaction to extreme trauma – diagnosed among children.

George Newhouse, principal solicitor at the National Justice Project, said the need for urgent medical care and offshore transfer requests had “grown exponentially” in 2018 and the government’s legal costs were likely to be much higher for this financial year.

“You cannot measure the damage that our government is doing to these poor children and people in dollars, but if our leaders ignore their moral and legal duty to desperately ill kids, then perhaps they might be more cautious and caring if they are forced to confront the economic cost,” Newhouse said.

Opposition spokesman for immigration, Shayne Neumann, accused Dutton of using taxpayer money to “stifle” the transfer process in the Australian-funded centres.

“These decisions are too important and pressing, particularly when they involve children, and should be left to medical professionals; not departmental bureaucrats,” he said, adding that transfers should be facilitated when recommended treatments were not available on Nauru.

Recently the Nauruan government has begun blocking transfers even when the federal court has ordered it – effectively rendering the home affairs department in breach of orders – but observers have suggested this was probably confined to the time period that Nauru was hosting the Pacific Islands Forum, and was particularly sensitive to the perception it could not provide adequate medical care.

Federal court justice Debbie Mortimer last week said that problem was Australia’s creation, given it entered into offshore processing with Nauru in the first place, and urged a political solution.

Recent federal court judgements have been scathing of the federal government, and in at least one case the sitting judge, Tom Thawley, awarded costs to the applicant, potentially further increasing the cost to government.

In delivering one judgement on 3 September, Mortimer noted there had been “at least 17” urgent medical transfer cases at that point.

Mortimer criticised the department and minister for home affairs for failing to quickly provide relevant information requested by the court, noting that a significant amount of it was in their hands and the hands of their contractors, not with the detainee.

“There is no longer any excuse for the respondents, in particular at departmental and agency level, not having systems in place to respond quickly, effectively and appropriately to these applications.”

There is a growing dissatisfaction among Australia’s institutions, peak bodies, charities, and human rights groups over the continuing government policies towards all people held on Nauru and Manus Island, but particularly children.

On Thursday the Royal Australasian College of Physicians, the Australasian College for Emergency Medicine and the Australian Medical Students Association joined the #doctorsforasylum campaign.

“As doctors we have compelling evidence that detention and uncertainty is damaging to people’s health and wellbeing and that this damage can be severe and lifelong,” said Professor Paul Colditz, a paediatrician and president of the RACP’s Paediatrics and Child Health Division.

“This is especially the case for children, who are very vulnerable to their parents’ mental health and negative, unsafe environments.”

More than 180 charities and organisations, including World Vision, the Australian Council for International Development, the Refugee Council of Australia and the Australian Lawyers Alliance, are now petitioning the government, giving it until 20 November – Universal Children’s Day – to have families transferred to Australia or another safe third country.

Last week the Australian Medical Association also called for families to be brought to Australia, with president Tony Barton telling the prime minister it was “a humanitarian emergency requiring urgent intervention”.

Morrison rejected the call.

• This article and its headline were amended on 22 October 2018 after the Department of Home Affairs provided a corrected figure of $275,000 to Senate estimates.

