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.
The Turkish foreign minister has spoken to the UK's Ambassador to Turkey about allegations that British intelligence agencies spied on G20 delegates during the 2009 summit, the Foreign Office confirmed.
An FCO spokesperson said: “We can confirm that the Turkish Ministry of Foreign Affairs has raised this issue with the Ambassador, which was discussed in a phone call”.
The South African government has expressed concern following allegations that British intelligence agencies spied on G20 delegates during the 2009 summit.
The administration said in a statement:
We do not yet have the full benefit of details reported on, but in principle we would condemn the abuse of privacy and basic human rights particularly if it emanates from those who claim to be democrats.
We have solid, strong and cordial relations with the United Kingdom and would call on their Government to investigate this matter fully with a view to take strong and visible action against any perpetrators.
Some politicians attempted to play down the latest GCHQ spying claims by suggesting it is "silly" to be surprised by British surveillance of other governments.
Glyn Davies is a Conservative MP for Montgomeryshire in Wales:
Do bears **** in the woods? Is the Pope Catholic? Are wind farms an obscenity? Does GCHQ spy on other Gov'ts. Yes Guardian looks very sillyFrom @GlynDaviesMP on Twitter:
Labour MP Jonathan Reynolds shared his sentiment:
Our intelligence services are involved in espionage?! No way!From @jreynoldsMP on Twitter:
But Conservative MP Mark Pritchard said that revealing British intelligence capabilities was "certainly not in the 'national interest'."
The Guardian may claim that GCHQ story is in the 'public interest' - but it is certainly not in the 'national interest'.From @MPritchardMP on Twitter:
The Guardian said the details of the alleged spying operation were contained in documents obtained by Edward Snowden, the US National Security Agency (NSA) whistle-blower responsible for a string of disclosures about US intelligence operations.
Traditionally friendly powers such as South Africa and Turkey were among the countries targeted during the course of a British intelligence operation at two G20 summit meetings in London in 2009, the Guardian claims.
A paper seen by the newspaper suggested the operation was sanctioned at a senior level in the government of then prime minister Gordon Brown and that the intelligence obtained was passed to ministers.
The disclosure is potentially embarrassing for Prime Minister David Cameron as he prepares to welcome leaders to the G8 summit at Lough Erne in Northern Ireland.
The Guardian says it has seen documents showing that foreign politicians and officials who took part in two G20 summit meetings in London in 2009 had their computers and phone calls intercepted by British intelligence agencies.
The newspaper claims one tactic used was to set up internet cafes where delegates' email traffic was read.
It says that the documents suggest the surveillance operation was "sanctioned in principle at a senior level in the government" and that intelligence was made available to British ministers.
The allegations are likely to raise questions as Britain prepares to host the G8 summit in Enniskillen, Northern Ireland tomorrow.
William Hague told the Commons the changing nature of terrorist threats had only increased the importance of Britain's intelligence relationship with the US. But the Foreign Secretary dismissed accusations that GCHQ had used its relationship with the United States to get around UK law.
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.
Prime Minister David Camerson said Britain's security agencies operated within the law and were subject to "proper scrutiny."
Foreign Secretary William Hague will address the House of Commons later amidst accusations Britain's GCHQ was involved in the NSA surveillance programmes.
Deputy Political Editor Chris Ship reports.