The Turnbull government minister in charge of scrapping generous travel entitlements for former MPs was himself a major beneficiary of the scheme, racking up almost $90,000 in taxpayer-funded flights.

Prime Minister Malcolm Turnbull appointed key supporter Mal Brough to the role of Special Minister of State in his September cabinet reshuffle, making him responsible for politicians' perks.

Under the portfolio Mr Brough has carriage of the Parliamentary Entitlements Legislation Amendment Bill, an Abbott government budget bill that seeks to abolish the controversial Life Gold Pass that entitles former MPs and their spouses to free domestic airfares.

But Finance Department figures reveal Mr Brough was himself an avid user of the pass. Between July 2008 and December 2012 Mr Brough claimed $87,637 worth of travel under the scheme – about $57,000 for himself and $30,000 for family members.

Mr Brough was a high-profile and sometimes controversial minister in the Howard government but lost his Queensland seat when Labor won power in 2007, leading to six years in the political wilderness. He was elected to another seat when Tony Abbott won power in 2013.

He supported Mr Turnbull in September's leadership coup and was promptly promoted back to the frontbench.

Now he's facing questions about if and when the government will proceed with the post-parliament travel crackdown, expected to save the public around $1 million a year.

The bill passed parliament's lower house with bipartisan support more than a year ago but has since mysteriously stalled in the Senate.

The government has not brought the bill on for debate even though it is expected to pass easily with Labor, Greens and crossbench support. While the bill is still listed on the Senate notice paper it's now not expected to come back on this year.

Asked to explain the delay, a spokesperson for Mr Brough said: "Minister Brough has been in the role of Special Minister of State for six weeks. There has been no change of policy regarding the abolition of the Life Gold Pass."

But the Australian Greens are calling on Mr Brough to explain what's going on, saying the perk is as out of date as Mr Abbott's Knights and Dames honours, recently abolished by Mr Turnbull.

"Gold passes should be immediately abolished," Greens democracy spokeswoman Lee Rhiannon​ told Fairfax Media.

"The government's go slow on its own legislation suggests it is not serious about cleaning up how MPs use their allowances."

The Life Gold Pass once offered former MPs unlimited travel on the public purse. Changes in 2002 limited that to 25 return flights a year and further changes in 2012 limited it to 10 return flights. The Gillard government scrapped it altogether for MPs retiring post-2012.

But some former MPs aren't giving up on the perk without a fight.

The Association of Former Members of the Parliament of Australia has been a vocal critic of the new bill. And in the High Court, a group of former Labor and Liberal MPs recently launched a challenge against the 2002 and 2012 changes.

They are seeking to use section 51 of the constitution – made famous in the classic Australian comedy The Castle – to argue the changes to their post-parliament perks represented an unlawful acquisition of their property by the Commonwealth.

The Commonwealth officially responded to the challenge late last month, saying the perks – including retirement allowances and the Life Gold Pass – "did not have the character of property" under section 51.

"The Commonwealth says that the plaintiffs are not entitled to the relief as alleged, or at all," it says in court documents obtained by Fairfax Media.

The case is due back before the court in December.

Mal Brough flew high on parliamentary perk he is now in charge of abolishing