The federal treasurer, Josh Frydenberg, will learn on Tuesday if he is ineligible to sit in the Australian parliament, just days before he is expected to unveil the second round of stimulus to combat the economic effects of Covid-19.

Frydenberg’s eligibility has been challenged in the federal court by a Kooyong constituent, Michael Staindl, who alleges he is disqualified by section 44(1) of the constitution because he is a citizen of Hungary, which Frydenberg denies.

The federal court heard the challenge in February. Chief justice James Allsop, justices Susan Kenny and Alan Robertson are listed to give judgment on Tuesday at 2:15pm in Sydney and Melbourne.

While a favourable ruling for Frydenberg would lift a constitutional cloud hanging over the deputy Liberal leader, the judgment also has the potential to eject the federal treasurer from parliament as he puts together Australia’s economic response to the coronavirus and to re-enliven questions about the validity of ministerial decisions made by ineligible MPs.

On Thursday the federal government unveiled a $17.6bn package to boost the Australian economy and has already signalled a second round of stimulus is coming for sectors including airlines, tourism, events, sport and the arts.

On Monday Frydenberg met Scott Morrison, finance minister Mathias Cormann and cabinet colleagues with portfolios on the frontline of the unfolding economic shock, before a cabinet meeting on Tuesday, with a package to follow as early as Thursday.

Events are moving so rapidly the government is telegraphing round two even though it is yet to legislate its first tranche of stimulus measures. Legislating round one will happen next week, with parliament expected to gather for a short session with the building in a partial lockdown.

The federal court case against Frydenberg is the first eligibility challenge of the 46th parliament, after the 45th parliament was rocked by 14 MPs or senators resigning or being ruled ineligible due to dual citizenship.

In October 2017 the high court adopted a strict interpretation of the bar on foreign citizens, disqualifying then deputy prime minister Barnaby Joyce and four senators because they had failed to renounce dual citizenships before nominating for parliament.

If Frydenberg were disqualified, on one reading of the constitution, he could continue as treasurer from outside the parliament for a period of three months.

Before the Joyce high court decision, constitutional experts including Anne Twomey and George Williams doubted that proposition, with both noting in comments to Guardian Australian that ineligibility would be backdated to the election and the three month period would have already elapsed.

If he were ineligible Frydenberg could renounce Hungarian citizenship and seek re-election at a byelection, following Joyce and every other MP who lost their lower house seat in the 45th parliament only to return with a fresh mandate.

According to his eligibility declaration, Frydenberg’s maternal grandparents were born in Hungary, giving birth to his mother there in 1943. Nevertheless, Frydenberg declared he had never been the subject or citizen of any country other than Australia.

Frydenberg’s lawyers told the court in February the challenge should be thrown out because the MP’s mother, Erica Strauss, was rendered stateless after fleeing Hungary with her family in 1949.

“A precondition to renounce [citizenship] is establishing to the satisfaction of the government that you are a citizen and in this case the Hungarian government does not recognise the respondent as a citizen,” John Sheahan QC said.

He added there was a letter from the Hungarian prime minister’s office on 19 November confirming Frydenberg’s Hungarian citizenship had not been established.