“The Security Service has reprioritized its work to enable them to counter potential threats from al Qaeda and its affiliates; (Irish) Republican dissidents; hostile states and others in the run-up to or during the Games,” Rifkind said.

“This, combined with the burden of the accreditation process (for the Games) and related work, has placed the Security Service under significant pressure over the past year.”

The committee also said cyber attacks presented a serious risk to Britain’s security and questioned if enough progress had been made on plans for a 650 million pound ($1 billion) National Cyber Security Programme announced 18 months ago.

“More needs to be done if we are to keep ahead in this fast-paced field,” Rifkind said.