Richard Barrett, the former head of counter-terrorism at MI6, has told ITV News that despite today's new airport security measures, the US has a "hell of a task" keeping track of would-be terror attackers.
He said that while Britain may be considered a "softer target" for any terror group with global aspirations, the threat to the UK is not much smaller than it is to the US, and in many ways it is "easier to attack Britain".
More top news
Temperatures recovering over the next few days.
An ambulance crew member told ITV News waiting outside hospitals to offload patients has become 'completely soul-destroying'.