LONDON, Feb 8: The CIA has recruited record numbers of informants in the Pakistani community in the UK to monitor “the 2,000 terrorist suspects” identified by MI5.

According to a report in the Sunday Telegraph — CIA warns Barack Obama that British terrorists are the biggest threat to the US — filed from Washington by Tim Shipman, the CIA has concluded from various reports that a ‘British-born Pakistani extremist’ entering the US under the visa waiver programme would be the most likely source of another terrorist spectacular on American soil.

The US spy agency has, therefore, decided to launch a vast spying operation in the UK to prevent ‘a repeat of the 9/11 attacks being launched from Britain’.

A British intelligence source revealed that a staggering four out of 10 CIA operations designed to thwart direct attacks on the US are now conducted against targets in Britain.

And a former CIA officer who has advised Mr Obama told The Sunday Telegraph that the CIA had stepped up its efforts in the last month after the Mumbai massacre laid bare the threat from Lashkar-e-Taiba, the militant group behind the attacks, which had an extensive web of supporters in the UK.

The CIA has already spent 18 months developing a network of agents in Britain to combat Al Qaeda, unprecedented in size within the borders of such a close ally, according to intelligence sources in both London and Washington.

Bruce Riedel, a former CIA officer, told The Sunday Telegraph: “The British Pakistani community is recognised as probably Al Qaeda’s best mechanism for launching an attack against North America.

“The American security establishment believes that danger continues and there’s very intimate cooperation between our security services to monitor that.”

Mr Riedel, who served three presidents as a Middle East expert on the White House National Security Council, added: “President Obama’s national security team are well aware that this is a serious threat.”

The British official said: “The Americans run their own assets in the Pakistani community; they get their own intelligence. There’s close cooperation with MI5 but they don’t tell us the names of all their sources.

“Around 40 per cent of CIA activity on homeland threats is now in the UK. This is quite unprecedented.”

Information gleaned by CIA spies in Britain has already helped thwart several terrorist attacks in the UK.