Clare Short has come under fire in the House of Commons following her claims about British Spying at the United Nations.

Labour loyalist George Foulkes continued his criticism of the former international development secretary during Foreign Office questions on Tuesday.

He said Short's claims about the alleged bugging had "changed from day to day". 

"Is it not clear that she probably hasn't breached the Official Secrets Act but she has been irresponsible to a very very great degree?" he asked the foreign secretary.

Jack Straw replied that Short's inconsistency showed the "sense" of the government not commenting on claims about the security services.

He added that the claims were "utterly irresponsible".

However, signs of the unease that Short's remarks have caused came from Neil Gerrard.

The London Labour MP warned ministers that the question of spying at the UN "will not go away".

But Conservative MP Boris Johnson said Short was "patently in breach" of the Official Secrets Act.

"And frankly this government is too spineless and too guilt-ridden to do anything about it," he added.

Straw said decisions on any prosecution were made by the director of public prosecutions with the consent of the attorney general, not on the basis of the government's interests.

The foreign secretary also revealed that Britain has responded to Mexican concerns that the UK spied on their mission at the UN in New York.

But Straw added that "there can be no speculation or no comment, either to confirm or deny, reports claiming details about the nature of British intelligence activities".

"What however I would say and make very clear is that the British intelligence and security services operate strictly in accordance with statutory provisions and requirements laid down by this House and the [Lords], and those obligations take full account of our obligations and international law," he added.

Conservative frontbencher Hugh Robertson said that steps should be taken to prevent further leaks from GCHQ "before lasting damage is done both to the transatlantic intelligence relationship and indeed the confidence and crucially the safety of our own intelligence services".

Straw said the government was "taking the necessary steps" to prevent a repetition but said that from time to time such incidents had happened in many countries.

For the Liberal Democrats, Sir Menzies Campbell said that as a permanent member of the UN security council Britain "has a special responsibility to protect the integrity and independence of the council and to uphold the office of the secretary general".

He said that any bugging would be "a serious breach of that responsibility".

Straw said he agreed that Britain had a responsibility, but repeated that he could not confirm or deny reports about intelligence activities.