The Deputy Prime Minister flew to Melbourne with his wife on a RAAF jet to watch the Melbourne Cup and justified the taxpayer-funded trip by reannouncing a three-year-old funding promise for a sports hall.
Last year, Michael McCormack was given tickets to Flemington's exclusive Birdcage section by gambling giant Tabcorp, a Guardian Australia investigation revealed.
He and his wife, Catherine Shaw, took an RAAF special purpose jet - which costs taxpayers about $4600 per hour - to fly into Melbourne on the Sunday.
Mr McCormack made the funding announcement on Monday, attended the race on Tuesday, and flew out at public expense on Wednesday.
The Deputy PM and Nationals leader said the trip to Melbourne necessary to make an announcement a day before the big race, for $4 million in funding for an indoor sports facility being built by Stonnington City Council in south-eastern Melbourne
However, local councils expressed their disappointment by the visit, as the money had already been announced three years ago by former Higgins MP Kelly O'Dwyer three years earlier.
The project is also bogged down in legal proceedings in the Victorian supreme court that have prevented works from commencing.
Internal council correspondence shows local councillors were shocked and disappointed by the announcement.
"This is quite extraordinary: what is the real purpose of this media event?" Cr Sally Davis, asked the council's chief executive.
"Kelly O'Dwyer announced/promoted this $4m election promise three years ago; so what is the rationale behind this repeat announcement?"
Mr McCormack also attended the Australian Hotels Association Melbourne Cup-eve lunch on the Monday.
A spokeswoman for McCormack said the Independent Parliamentary Expenses Authority (IPEA) had already confirmed the travel claims, including the use of family reunion travel, were within the rules.
"The deputy prime minister travels in accordance with the guidelines set by the Independent Parliamentary Expenses Authority (IPEA)," the spokeswoman said.
"[The IPEA] has confirmed the deputy prime minister's parliamentary and ministerial work in Melbourne, where he was acting prime minister from 3 to 5 November 2019, accompanied by Mrs McCormack, adheres to the guidelines."
To claim travel expenses, including family travel, MPs must be travelling for the dominant purpose of parliamentary business.
The rules also state that claims for travel allowance must be "value for money" and incurred in good faith, and that MPs must be "able to publicly defend the expense".
In February, Mr McCormack came under fire for organising a party room meeting in Melbourne to coincide with the Nationals' 100th anniversary celebrations in Melbourne, allowing politicians to charge taxpayers for flights and accommodation for the lavish party.