I am today announcing changes to the terrorism threat level system. As recommended in the Operational Improvement Review, the Joint Terrorism Analysis Centre have taken an increased role in assessing all form of terrorism, irrespective of the ideology that inspires them.
The national threat level system will now take account of the assessments from all forms of terrorism, including Islamist, Northern Ireland, and extreme right-wing. The threat from Northern Ireland-related terrorism in Northern Ireland will remain separate from the national threat level.
Also, to ensure clarity in the threat level system, I am also announcing the change in definition of the LOW, SUBSTANTIAL and CRITICAL threat levels. The threat levels will now be defined as below:
• CRITICAL meaning an attack is highly likely in the near future
• SEVERE meaning an attack is highly likely
• SUBSTANTIAL meaning an attack is likely
• MODERATE meaning an attack is possible but not likely
• LOW meaning an attack is highly unlikely
The changes made today do not affect the current threat level. The threat level to the UK from terrorism remains at SEVERE, and the threat level to Northern Ireland from Northern Ireland-related terrorism also remains at SEVERE, meaning that an attack is highly likely.
Threat levels are designed to give a broad indication of the likelihood of a terrorist attack. They are a tool for security practitioners working across different sectors and the police to use in determining what protective security response may be required. They also keep the public informed and give context to the protective security measures which we all encounter in our daily lives.
There remains a real and serious threat against the United Kingdom from terrorism and I would ask the public to remain vigilant and to report any suspicious activity to the police regardless of the threat level.
The decision to change the terrorism threat levels are taken by taken by the Joint Terrorism Analysis Centre independent from Ministers. The Joint Terrorism Analysis Centre set the national threat level and the Security Service set the Northern Ireland-related Terrorism in Northern Ireland threat level. These are based on the very latest intelligence, considering factors such as capability, intent and timescale. Threat levels are kept under constant review.