The Department of Home Affairs says its spending on entertainment and office upgrades has been reasonable and necessary, after Labor declared it excessive.
Answers to Senate Estimates questions posed by Labor's Catryna Bilyk revealed the department spent more than $450,000 on corporate hospitality and $100,000 on executive office upgrades in 2017/18.
Labor's immigration spokesman Shayne Neumann says the figures reflect an "excessive and completely unacceptable" spending of taxpayers' money.
He said the Australian Border Force had to curtail patrols late last year to save money on fuel, illustrating Homes Affairs Minister Peter Dutton's priorities.
"It is unacceptable that Peter Dutton has prioritised spending more than half a million of taxpayers' dollars on entertainment and office furniture over national security," Mr Neumann said in a statement on Friday.
But the department says the expenses are "reasonable and requisite for the corporate functions of a government department".
"Spending on hospitality for the 2017-18 financial year is proportionate to the scale of the department's broad national security mandate, and the stakeholder management and footprint required to deliver its objectives," a spokesman for the department said in a statement on Friday.
The formation of the home affairs portfolio in late 2017 also required some staff allocations, it said.
The department includes the former Department of Immigration and Border Protection and some elements of the attorney-general's office.
Changes such as the reduction in ABF patrols happened this financial year and not in the year Labor is focused on, the department has also noted.
"It is incorrect to imply any form of trade-off between the activities referenced as they relate to distinct financial years."
Australian Associated Press