MR Helmut Kohl, the German Chancellor, said yesterday the Maastricht criteria for European monetary union (EMU) were not open to debate, and that it was important to keep to the planned timetable. EMU is due to begin on January 1st 1999.

"The completion of EMU is a central building block for the house of Europe," Mr Kohl said, according to the text of a speech prepared for delivery at the opening of the Hanover Industry Trade Fair.

"Of course the Maastricht stability criteria are not subject to debate. It is also important to stick to the timetable for the euro," he said.

Economic data for 1997 will be the basis for determining which nations participate in EMU at the start. Germany says it will meet the criteria, but most observers expect its deficit will exceed the threshold of 3 per cent of economic output. Such forecasts are fuelling speculation that the start of EMU will be delayed, despite repeated official statements to the contrary.