The cost of Parliament's dual citizenship imbroglio has been laid bare in the Turnbull government's mid-year budget update.
Taxpayers will fork out $11.6 million in the 2017-18 financial year for legal costs arising from the saga, which has dragged on for nearly half a year and seen a slew of MPs appear before the High Court.
Some of Australia's top silks were enlisted to battle it out in the landmark 'citizenship seven' case, which ended with five MPs including Deputy Prime Minister Barnaby Joyce, deputy Nationals leader Fiona Nash and One Nation senator Malcolm Roberts being thrown out of Parliament.
Mr Joyce was represented by leading barrister Bret Walker SC. Former solicitor-general Justin Gleeson SC and former Federal Court judge Ron Merkel QC represented Mr Joyce's challenger at the 2016 election, Tony Windsor, who argued for the Nationals leader's elimination.
Another of the 24 barristers who got a call-up was Robert Newlinds SC, who acted for Mr Roberts.
Elite lawyers can command fees of up to five-figures a day.
In October, Attorney-General George Brandis defended the expense as in the public interest.
"It is the practice - and it's been a longstanding - that when there is a very important matter of constitutional principle at issue then the Commonwealth pays the costs," Senator Brandis said.
The High Court, sitting as the Court of Disputed Returns, will consider further cases in early 2018.
In the last session of Parliament for 2017, Labor senator Katy Gallagher and Labor MP David Feeney were referred following doubts about whether they had met the requirements of section 44.
The government has warned it might use its numbers to send more suspect Labor and crossbench MPs to the High Court for a final verdict on their eligibility.