The federal government has announced it will close the Christmas Island detention centre, just weeks after reopening it at a cost of more than $185m. Not a single refugee or asylum seeker has been transferred there.

The government reopened the detention centre in reaction to the passing of the medical evacuation bill, ensuring refugees and asylum seekers on Manus Island and Nauru could be evacuated to Australia for treatment if required.

The bill sparked furious partisan disagreements over Australia’s medical obligations to those it sent to offshore processing centres, as well as border security and asylum seeker policy.

Tuesday’s budget reiterated the government’s intention to repeal the bill, and also announced it would close the centre before 1 July.

“Any illegal maritime arrivals on Christmas Island will be returned to Nauru and Papua New Guinea, and the… detention centre will be returned to a contingency setting,” it said.

The government’s health contractor, IHMS, has been engaged to provide health workers and specialists on the island – where limited services exist.

The budget papers revealed the cost of that to be $161.4m this financial year, and $23.7m next financial year – taking into account the plan to close the centre. At the time the centre was reopened, the government claimed the cost would run to billions of dollars.

The costs in the budget include $178.9m to manage the transfer of people from Nauru and Manus Island to Christmas Island for treatment, $3.2m to increase the presence of Australian federal police on the island, and another $3m to “reinforce” the Operation Sovereign Borders offshore strategic communications campaign.”

Buzzfeed reported $106m of the cost was for garrison and welfare services including healthcare, which isn’t treating anyone yet and won’t be made available to Christmas Island residents.

The medical evacuation law has been in place for more than six weeks, but Guardian Australia revealed earlier on Tuesday just one person is thought to have been transferred under its provisions.

The law includes an independent panel made up of government and non-government medical experts to review any case where the minister refuses to accept a recommendation for transfer. The federal budget included $8m for this financial year to establish the panel, which it said would “monitor, assess, and report on the physical and mental health of transitory persons who are in regional processing countries and the standard of health services provided to them”.

The panel is yet to sit, and member organisations have not been briefed or had most of their nominees to sit on the panel confirmed. The positions are unpaid.

Tuesday’s budget papers also said newly arrived refugees would be given longer before being forced to comply with government job seeking requirements, in a move that would save the government almost $80m.

The changes to refugee work rules – described in the budget as “streamlining the employment servicing arrangements” – suggests it is beneficial to both refugees and to the government bottom line to give people more time to learn English and find stable housing before making them join the Jobactive employment program.

Newly arrived refugees would not be made to look for work until they had been receiving income support for 12 months. Currently refugees are made to join Jobactive after six months on income support, and for some time after that they are then receiving support services from both programs.

The Department of Jobs and Small Business estimates 3,200 fewer refugees will join Jobactive each year under the new measures, which department officials said gave more support but was better targeted, thus delivering savings.

Eligible refugees could choose to use Jobactive services at any point if they wished and about 520 are predicted to opt-in annually.

The savings of $7.7m in this current financial year, then $21.8m, $23.1m, and $25.5m in the years following, would be redirected elsewhere.