ECB executive board member Joerg Asmussen, in an interview to be broadcast on hr-info public radio later on Wednesday, said he backed a call by German Finance Minister Wolfgang Schaeuble for a stronger role to be handed to the EU's Economic and Monetary Affairs commissioner.

"It would be a good idea for the monetary affairs commissioner to reject a budget," Asmussen said.

But it would still be up to the countries -- and not the commissioner -- to solve the problems, the ECB official continued.

"How the budget will be fixed will be up to the member state," he said.

On Tuesday, Schaeuble had called for the commissioner's role to be beefed up so as to be able to send back budgets to national parliaments.

Further, the EU treaty must be changed to improve democracy at the European Parliament, Schaeuble argued.

Germany will propose that only members involved in a specific issue be allowed to vote on it.

For example, those countries which are not signed up to the Schengen agreement, allowing free passage of citizens to most countries in the EU, would not be permitted to vote on the matter.

Likewise, eurozone members of parliament would be able to vote on eurozone issues, but not those outside the bloc, Schaeuble suggested, saying a convention to agree on the treaty changes would ideally be held in December.