The UK terror threat level has been raised to severe which means an attack is highly likely following incidents in Austria and France
Priti Patel, the Home Secretary, is expected to say the upgrading of the threat level from substantial was a precautionary measure after the horrific terror attacks in Vienna, Paris and Nice which have left eight people dead.
The decision by the Joint Terrorism Analysis Centre (JTAC) to raise the level to severe means a terror attack is now highly likely rather than likely. It is one below the highest level of critical which means an attack is highly likely in the near future.
The killings in Austria and France came on the eve of their national lockdowns and, with the Government about to impose similar restrictions in England on Thursday, counter-terror chiefs are believed to have been concerned about potential copycat attacks.
Home Office sources said the public should be alert but not alarmed by the upgrading of the threat level which was last at severe exactly a year ago.
A former terror chief said: Whenever there is a peak of interest and attacks in other countries, it does inspire the unhinged Islamists here and raises the prospect of copycat attacks.
There will be a lot of activity by counter-terror police and MI5 to keep an eye on the more unstable characters to make sure they are not inspired to do anything.
The current threat level system was introduced in July last year, so that the assessment reflected the threat posed by all forms of terrorism, irrespective of ideology and covering extreme right and leftwing terrorism.
The threat level under the previous system was last raised from substantial to severe in August 2014 against a backdrop of increasing terrorist activity in Syria and Iraq, including the growth of Islamic State.
It remained at severe for five years, until November 3, 2019 against a backdrop of rising terrorist activity culminating in the multiple deaths in terror attacks in London and Manchester in 2017.
Austrian police yesterday urged people to stay indoors as they hunted for suspects after a multiple gun attack by a 20 year old Islamist terrorist in the capital Vienna that killed two men and two women.
It followed an attack by 29-year-old Tunisian man in Nice last Thursday which left three people dead including a church sexton. A French middle-school teacher was killed and beheaded in a separate terror attack two weeks previously in Paris on October 16.