The German central bank has again stirred up debate about the 1999 launch of the European single currency, but Chancellor Dr Helmut Kohl said he was confident it would start on time.

The Bundesbank chief economist, Mr Otmar Issing, reopened the issue yesterday by saying that uncertainty about the euro in the run-up to monetary union could lead to market instability that could threaten the launch. But the Chancellor's office said in a statement that Dr Kohl wanted the planned single currency to start on time and with strict adherence to the entry criteria.

EU finance ministers and central bankers preparing for a meeting in the Luxembourg spa town of Mondorf-les-Bains this weekend will be trying as hard as possible not to raise further speculation about the issue.

In a Berlin speech, Mr Issing warned that the trend toward lower German inflation was over and the central bank was concerned about price trends.

He added that uncertainty about the euro in the run-up to the planned 1999 start of monetary union could lead to market instability.

But he said he did not expect such dramatic problems. "I don't think this is likely, but such a crisis should be avoided."