Officials from the National Anti-Corruption Commission searched the 30-year-old's home in June 2024 over allegations he misappropriated secret documents related to French submarines five years earlier.
Lehrmann denies the allegation and has sought assistance from the federal government to cover his legal costs of the raid.
This request was rejected by federal Special Minister of State Don Farrell on October 22, the law student revealed in a brief Federal Court hearing on Tuesday.
After failing to hear back about funding for more than a year, Lehrmann has sued Mr Farrell and NACC Commissioner Paul Brereton seeking court orders forcing an outcome.
With a rejection now issued by the minister, the 30-year-old told the Federal Court in Hobart he would amend his case to call for a judicial review of the decision.
While mediation between the parties was called off due to the change in circumstances, Mr Farrell and Mr Brereton's barrister Bora Kaplan SC said his clients would be willing to sit down with Lehrmann in the future.
The former staffer revealed he had also made a request for funding to federal Attorney-General Michelle Rowland.
While a hearing has been set down for February, Lehrmann indicated he was prepared to call for an urgent hearing sooner, fearing Christmas raids from the anti-corruption watchdog.
The watchdog could retaliate after being targeted by Lehrmann's lawsuit and had not given an undertaking it would make no further moves against him before February, he told Justice Brigitte Markovic.
"The orders I seek don't prejudice a new NACC investigation if they think I stole US submarine secrets now," he said.
In October, Lehrmann told the court investigators seized two personal diaries during the raid on his home.
He claims the probe was spurred by "frivolous, James Bond like allegations".
Lehrmann is accused of gathering the confidential information in March 2019, days after he allegedly raped his colleague Brittany Higgins in Parliament House.
He has denied the sexual assault claims, which remain untested in a criminal court after a 2022 trial in the ACT was abandoned due to juror misconduct.
But Federal Court Justice Michael Lee found in 2024 the allegations he raped Ms Higgins were proven on the balance of probabilities and dismissed his defamation suit against Network Ten and presenter Lisa Wilkinson.
Lehrmann has appealed against the defamation loss.
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