UK & World News
MI5 Boss Warns Of Growing UK Terror Threat
Britain will face at least one attempted major terror attack every year for the next few years, the head of MI5 has warned.
In his first speech since taking over the Security Service in April, Andrew Parker told a private audience at the Royal United Services Institute: "Since 2000, we have seen serious attempts at major acts of terrorism in this country typically once or twice a year.
"That feels to me, for the moment, unlikely to change."
Among the reasons for this are the increasing numbers of Britons going to Syria to try to become jihadists.
In his off-camera speech, Mr Parker said: "A growing proportion of our casework now has some link to Syria, mostly concerning individuals from the UK who have travelled to fight there or who aspire to do so.
"Al Nusrah and other extremist Sunni groups there aligned with al Qaeda aspire to attack Western countries."
More than any recent conflict, Syria has attracted would-be fighters from the UK.
Sky News understands that the number of individuals involved over the last three years is in the low hundreds.
The fear is some could return to the UK even more radicalised.
Mr Parker repeated a warning made by his predecessor, Jonathan Evans, saying: "It remains the case that there are several thousand Islamist extremists here who see the British people as a legitimate target."
He also mentioned the growing fears about terrorism in Northern Ireland after several incidents and the threat of more.
"Rejecting the political process in Northern Ireland, these ragged remnants of a bygone age are in a cul-de-sac of pointless violence and crime with little community support," he said.
"We will continue to work with the police to put these thugs and killers in front of the courts."
He then turned to the subject of how to combat these threats and the use of technology.
When former CIA contractor Edward Snowden leaked details about surveillance tactics, it is thought he inflicted massive damage on several spy agencies, including Britain's Government Communications Headquarters (GCHQ).
One source said some of the things leaked by Snowden amounted to "an instruction booklet on how to evade surveillance".
This explains why Mr Parker appears to have entered the debate about The Guardian newspaper's publication of some of Snowden's material.
The Guardian was not mentioned by name, but in his speech Mr Parker said: "It causes enormous damage to make public the reach and limits of GCHQ techniques.
"Such information hands the advantage to the terrorists. It is the gift they need to evade us and strike at will."
There are also passages explaining the thinking of MI5.
He accepts there are choices to be made about how and whether communications data is retained, but concludes: "We cannot work without tools."
The language used is temperate, but behind it you sense a passionate argument by a man who understands that there are sections of public opinion which deeply mistrust the security services.
He asks if it should be accepted "that terrorists should have means of communication that they can be confident are beyond the sight of MI5 or GCHQ acting with proper legal warrant. Does anyone actually believe that?"
It is for Parliament to decide the powers that MI5, MI6, and GCHQ should have, including access to the email of people they suspect of wrongdoing.
That is an ongoing debate which will be revisited when the heads of the three services give evidence to the Intelligence Select Committee next month.
David Cameron has given his full support to the controversial speech, with a No 10 spokesman saying: "The Prime Minister thinks it was an excellent speech."
He also supported Mr Parker's suggestion that intelligence leaks, and their publication, helped terrorists undermined the spy agencies efforts to keep people safe.
In a statement a Guardian News & Media spokesperson said: "A huge number of people - from President Obama to the US Director of National Intelligence, James Clapper - have now conceded that the Snowden revelations have prompted a debate which was both necessary and overdue.
"The President has even set up a review panel and there have been vigorous discussions in the US Congress and throughout Europe. Such a debate is only worthwhile if it is informed. That is what journalism should do."