The Nationals frontbencher was facing a legal challenge from a former Labor rival but the court has ruled the challenge invalid.
The seven judges of the High Court have blocked a Labor challenge to Nationals MP David Gillespie's eligibility to sit in parliament.
Labor argued Mr Gillespie should be ruled inelligible under Section 44 of the Contitution because he owned a shopping centre that received rental income from an Australia Post store.
The case was brought by the Labor candidate who Mr Gillespie defeated in the seat of Lyne, Peter Alley, who was acting as a "common informer".
But the High Court unanimously decided a court referral on a politician's eligibility must come from the House of Representatives, not from an individual member of the public.
Bret Walker, acting for Mr Alley, told the court it had the jurisdiction to rule on the case and did not need to wait for a referral. The court considered whether it could or should receive a referral under common informers legislation, ultimately deciding it could not.
The justices have not actually decided on the question of Mr Gillespie's eligibility. The court has only concluded the legal action brought by Mr Alley was invalid.
Labor could still trigger a High Court hearing on Mr Gillespie if it succeeded in passing a referral through the House of Representatives, where the Turnbull Government maintains a slim majority.
"The Court ordered that the proceeding under the Common Informers Act be stayed until the question of whether Dr Gillespie is incapable of sitting as a member of the House of Representatives is determined pursuant to s47 of the Constitution or s376 of the Electoral Act," the court said in a document explaining the decision.
- with AAP