The Western Australian National party has cancelled a planned $1,000 a head political fundraiser aboard a navy warship after it admitted the idea was “not appropriate”.

Paul Brown, a state Nationals MP, had sent out invitations promising “a unique luncheon experience with the Nationals WA leadership on-board the Australian navy warship, HMAS Perth”.

The promotion carried the banner “All aboard!” and foreshadowed access to the National party’s state leader, Terry Redman, the deputy leader, Mia Davies, and the state director, Jamie Forsyth.

A poster for a planned political fundraiser by the Western Australian Nationals party which was due to take place aboard a navy warship. Photograph: Supplied

Labor expressed outrage at the “utterly inappropriate” use of defence force assets and demanded an explanation of any approvals provided. The defence minister, Marise Payne, distanced herself from the scandal, saying her office and the Navy had no knowledge of the “regrettable” fundraising proposal.

Brown issued a statement on Thursday confirming the 15 January fundraiser had been cancelled. He blamed “internal excitement” within the WA Nationals.

“Shortly after the invitation was sent out [over the Christmas period], our own internal processes determined that holding a fundraiser on commonwealth property would not be appropriate, and we immediately cancelled the event,” he said.

“Time constraints and our own internal excitement led to an oversight in judgment, which we corrected at our earliest opportunity.”

Brown said the error occurred after he purchased a package – which included a tour of HMAS Perth, the use of a flight simulator and a group lunch – at a Royal Flying Doctor Service fundraising event.

He bought the package “in good faith” and intended “to put it to use in a positive way”. He now acknowledges the political fundraiser was not an appropriate way to use the package, and his new plan was to invite disadvantaged families to join him on HMAS Perth.

Payne said her office had no knowledge of the event.

“I am advised that Navy was not informed that the event, which was originally auctioned to raise money for the Royal Flying Doctor Service, was being billed as a political fundraiser,” the defence minister said on Thursday.

“Defence facilities should not be used for political fundraising purposes and it is regrettable that the original invitation was issued.”

State and federal Labor MPs criticised the proposal.

The federal opposition’s acting defence spokeswoman, Gai Brodtmann, asked who knew about the fundraiser, who authorised it and when it was approved.

“It is utterly inappropriate for such an event to be held on any ADF facility or asset and the defence minister must explain how this could be allowed to happen,” she said.

The WA Labor spokesman on defence issues, Paul Papalia, said the episode was “an absolute disgrace” and called for an inquiry.

“A non-partisan apolitical defence force is a central pillar of the Australian democracy,” he said. “Everyone knows that, the military know it, it appears though that the National Party of Western Australia just don’t have a clue.”