The president of Germany’s powerful Bundesbank has firmly rebuffed international demands for decisive intervention in the bond markets by the European Central Bank to combat the eurozone debt crisis, warning that such steps would add to instability by violating European law.

Bundesbank president Jens Weidmann told the Financial Times that only politicians could resolve the crisis, and he rejected the idea of using the ECB as “lender of last resort” to governments.

He also criticised actions taken by eurozone governments as “inconsistent”, and warned that their plans to involve private sector banks in rescue plans for Greece could add to the eurozone’s woes. Such private sector involvement, he said, could undermine market confidence in the eurozone’s crisis-fighting tools such as the rescue fund, the European financial stability facility.