The threat to Britain from international terrorism remains high but the menace of Irish dissident republicans has reduced, Home Secretary Theresa May announced today.
Giving details of the latest intelligence assessments by MI5, she said the international threat level remains unchanged at substantial, indicating that an attack is a strong possibility.
She said there continued to be a real and serious threat against the UK, appealing to the public to remain vigilant and report suspicious activity to police.
But the threat to Britain from violent Irish republicans, who continue to wage a sporadic campaign, has receded. Despite more than a dozen incidents within Northern Ireland this year, there has been no public sign of attempts to carry out bombings and shootings in England.
But in Northern Ireland the threat level remains unchanged at severe, indicating that attacks are highly likely.
The indications are however that increased security measures in Northern Ireland, put in place following the murders of two soldiers and a police officer in March 2009, are having a significant effect.
The authorities are nonetheless acutely aware that at any moment a dissident attack could take the lives of either security force personnel or civilians. Considerable resources therefore remain devoted to surveillance and the disruption of their activities.
A number of important dissident bombers and planners are currently behind bars, either awaiting trial or serving sentences. But there is concern that the recent release of one important figure may give a boost to the dissident campaign.
In recent years the security forces have seriously disrupted dissident attempts to smuggle in arms from mainland Europe. At the same time there are no signs of any increased support for dissident activity among the republican community.
In the Irish Republic meanwhile police have scored a number of successes with arrests and prosecutions.