Addressing the Commons this afternoon, the Foreign Secretary William Hague said the Government took great care to balance individual privacy with a duty to safeguard security.
The Government deplores the leaking of any classified information wherever it occurs. Such leaks can make the security of our own country and that of our allies more difficult.
The House will understand I will not be drawn in to confirming or denying any aspect of leaked information.
To intercept the content of any individual's communications in the UK requires a warrant signed by me, the Home Secretary or another Secretary of State. This is no casual process.
The Foreign Secretary said British intelligence would never use its partnership with the United States to get around UK laws.
GCHQ (Government Communications Headquarters) is one of three UK intelligence agencies that form the UK's security and intelligence system.
Facebook, Google and Microsoft have all denied claims that they cooperated with US intelligence agencies to gather data on foreign users.