FRANKFURT — In what could be interpreted as a subtle escalation of tension among top central bankers in the euro zone, the German Bundesbank said Tuesday that it welcomed plans by the country’s Constitutional Court to determine whether it was legal for the European Central Bank to buy government bonds.

The euro zone crisis has eased considerably since Mario Draghi, the president of the central bank, announced plans last month to hold down borrowing costs for Spain and other troubled countries by buying their bonds on the open market.

But Jens Weidmann, the president of the Bundesbank, has objected loudly to the bond-buying plan. He was the only member of the E.C.B.’s 23-member Governing Council to oppose the plan, arguing that it would violate a ban on using the central bank to finance governments.

Mr. Weidmann and Mr. Draghi have avoided open conflict. But Mr. Weidmann’s outspoken dissent on bond buying and other issues appears to have become an increasing annoyance to the E.C.B. president.