German finance minister Wolfgang Schaeuble has said the European Union would be "less stable" if Britain voted to leave in a referendum on 23 June.
Addressing a conference organised by the British Chambers of Commerce in London, Mr Schaeuble said: "I think the UK would take the risk that continental Europe would be less stable, more volatile."
Speaking at the same event, British Finance Minister George Osborne said it would be a mistake for Britain to leave the EU at a time of geopolitical instability and risks posed by developments in Russia, the Middle East and North Africa.
Mr Schaeuble said Britain was a force for improving the competitiveness of the bloc, adding that he did not want to lose an ally in the fight to reduce unnecessary rules and regulations.
When asked what Germany would do if Britain voted to leave the EU, he said "we would cry", prompting laughter and applause from the audience.