Two German regional elections this weekend are expected to bring more gains for a far-right party and could determine whether Chancellor Friedrich Merz can hold on to power and push ahead with economic reforms.

Germany’s would-be next chancellor, Friedrich Merz, won lawmakers’ approval Tuesday for ambitious plans to loosen the nation’s strict debt rules for higher defense spending as doubts mount about the strength of the trans-Atlantic alliance, and to set up an enormous fund for investment in its creaking infrastructure.