An investigation has been launched into the leaking of restaurant receipts for gatherings hosted by Defence Minister David Johnston.

The November dated receipts totalled $6384 and show purchases of $190 wine bottles and meals worth $300 a head and were published by News Corp Australia on Wednesday.

Defence is now investigating the leak.

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Senator Johnston’s office has said all hospitality spent on foreign dignitaries or industry heads is within guidelines and consistent with the practice of past defence ministers.

Meanwhile, his office has declined to comment on reports two senior staffers left this week.

“As per long standing practice, the minister does not discuss staffing matters,” a spokesperson told AAP.

Senator Johnston has faced opposition calls to resign after last week telling parliament he wouldn’t trust South Australian shipbuilder ASC to build a canoe, let alone Australia’s next fleet of submarines.

The minister has expressed regret for the remark, which he described as a “rhetorical flourish”.

Labor’s defence spokesman Stephen Conroy said Senator Johnston had been abandoned by his own colleagues.

“He’s lost the confidence of the prime minister and now he should do the right thing and resign,” he told reporters in Canberra.

South Australian Labor MP Nick Champion said the final day of parliament for the year was “a good day for another reset” and cabinet reshuffle.

“They had one on Monday, we can have another one today,” he said.