The parliamentary intelligence and security committee, which oversees the work of the intelligence agencies, said extremist elements in Syria were assessed to represent “the most worrying terrorist threat” to the UK and its allies.
In its annual report, the committee had “serious concern” about the security of the “vast stockpiles” of chemical weapons amassed by president Bashar al-Assad’s regime. They are thought to include sarin, ricin, mustard gas and VX – described as “the deadliest nerve agent ever created”.
MI6 chief Sir John Sawers told the committee there was the risk of “a highly worrying proliferation around the time of the regime fall”.
The committee said: “There has to be a significant risk that some of the country’s chemical weapons stockpile could fall into the hands of those with links to terrorism, in Syria or elsewhere in the region. If this happens, the consequences could be catastrophic.”
The committee also highlighted the threat to the UK of cyber attacks, which GCHQ said is “at its highest level ever and expected to rise further still”.
While foreign states continue to pose the greatest threat – the report highlighted the alleged involvement of China and Russia – the committee said there is evidence of some countries turning to private groups to carry out state-sponsored attacks.
“These state-affiliated groups consist of skilled cyber professionals, undertaking attacks on diverse targets such as financial institutions and energy companies,” the report said.
“These groups pose a threat in their own right, but it is the combination of their capability and the objectives of their state backers which makes them of particular concern.”