Germany's Greens may refuse to back plans by likely next chancellor Friedrich Merz for a massive increase in state borrowing, with a party source on Monday warning "approval is becoming less likely with each passing day".

Germany’s Green party rejected a draft debt-financed package that would unleash hundreds billions of euros in defense and infrastructure spending, potentially leaving chancellor-in-waiting Friedrich Merz without a supermajority needed to pass the legislation.

The Christian Democrat, whose party won the parliamentary elections, quickly began negotiating with the Social Democrats to secure a majority in parliament. The likely future chancellor insists the country cannot delay the military investments needed due to US disengagement.