October 17th, 2017 
(THE GUARDIAN) — By Vikram Dodd
Britain is facing its most severe ever terrorist threat and fresh attacks in the country are inevitable, according to the head of Britain’s normally secretive domestic intelligence service in a rare public speech.
Andrew Parker, the director general of MI5, said the UK had seen “a dramatic upshift in the threat” from Islamist terrorism this year, reflecting attacks that have taken place in Westminster, Manchester and London Bridge.
The spy chief said: “That threat is multi-dimensional, evolving rapidly and operating at a scale and pace we’ve not seen before.”
He added: “It’s at the highest tempo I have seen in my 34-year career. Today there is more terrorist activity, coming at us more quickly, and it can be harder to detect.”
MI5 is under pressure to demonstrate its effectiveness after four Islamist terrorist attacks escaped its detection this year.
Parker’s speech to specialist security journalists on Tuesday was his chance to frame the debate about Britain’s battle against Islamist terrorism at a time when the agency’s staff numbers are already expanding from 4,000 to 5,000.
This month the government will receive reports on whether chances to thwart the atrocities were missed and what lessons could be learned. Ministers and the National Security Council wanted independent oversight of the review, in essence not allowing MI5 or counter-terrorism police to assess themselves.
Parker said MI5 had stopped far more terror plots than those that caused mass casualties this year. He said 20 plots had been thwarted in the last four years.