Plans by Germany's chancellor-in-waiting Friedrich Merz to unleash a massive state borrowing programme were hit by last minute legal challenges from opposition parties announced on Monday ahead of a parliamentary vote.
The far-right Alternative for Germany challenged the vote at the constitutional court, arguing the Bundestag had not given time for outside experts to scrutinise plans that lifted the euro and shares last week.
Independent lawmaker Joana Cotar also said she had filed a complaint in order to scupper the vote, while three lawmakers from the pro-business Free Democrats (FDP) also plan petitions, the dpa news agency reported.
"The federal government has so far been unable to answer very simple and fundamental questions on this," FDP finance expert Florian Toncar told dpa.
Merz wants to push a 500 billion euro ($544 billion) infrastructure fund and sweeping changes to debt rules through the outgoing parliament as a way to revive ailing growth and boost defence spending in Europe's largest economy.
The parliamentary budget committee had approved the plans on Sunday. The measures have already survived earlier legal challenges last week from the AfD and the Left party.
Merz's conservatives and the Social Democrats (SPD), who are in talks to form a coalition government after elections last month, are jointly pushing the measures.
Separately, SPD co-chief Saskia Esken told the broadcaster ZDF on Monday that her party's leadership will speak with individual lawmakers within their own ranks who could be wavering before Tuesday's vote.
Merz cannot afford many defectors on Tuesday as his conservatives, SPD and Greens are set to clear the two thirds majority needed to pass constitutional amendments with just 30 votes to spare.
He has justified the urgent need to push the package through the outgoing parliament with recent shifts in U.S. policy under President Donald Trump, warning that a hostile Russia and an unreliable U.S. could leave the continent exposed.
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