The head of the German parliament's intelligence committee has called for inquiries into alleged spying by the British embassy in Berlin.
Thomas Oppermann said the committee had asked both Germany's law enforcement services and its intelligence services to investigate the alleged "crime".
A member of Chancellor Angela Merkel's Christian Democrat (CDU) party mooted a formal "no-spy" agreement with the UK.
The UK's ambassador was asked to attend the German foreign ministry on Tuesday.
Simon McDonald met Foreign Minister Guido Westerwelle, an embassy spokeswoman said, without giving details.