The transatlantic spying row engulfed Anglo-German relations yesterday when the British ambassador was called to the Foreign Ministry in Berlin and asked to explain reports of a secret listening post in the capital.
Germany took the highly unusual diplomatic step after it was claimed that Britain had been operating an eavesdropping post on the roof of its embassy near the Brandenburg Gate.
The embassy is close to the German Parliament, Chancellor Angela Merkel's office, government ministries and other foreign embassies.
In a sign of rising tensions over the issue, Guido Westerwelle, the German Foreign Minister, asked Simon McDonald, the British ambassador, to attend a meeting to explain the claims, which were published by the Independent.
They were said to be based on leaked documents from Edward Snowden, the former US National Security Agency contractor turned whistleblower, and aerial photographs.
Britain has followed the United States into Germany's displeasure, after Merkel protested to President Barack Obama about the bugging of her mobile phone by American intelligence. A Foreign Office spokesman confirmed that McDonald had "attended a meeting" with a senior German official.