The former head of Britain's counter-terrorism security force has told talkRADIO that the main threat facing the UK is homegrown but an attack could come at any time.
This weekend will mark the one-year anniversary of the attacks in Paris which left 130 dead and 352 people injured.
Islamic State terrorists launched a series of attacks across the French capital, including a suicide bombing outside the Stade de France and a shooting attack on the Bataclan theatre in the city's 11th arrondissement.
In the latter attack, the perpetrators took hostages, and it was only once they started to execute them that French special forces stormed the building and liberated it. Some of the victims are still in hospital one year later.
Chris Phillips, the former head of the national counter-terrorism security office, told talkRADIO that while the UK is "as prepared as any country in the world to deal with terrorism", the majority of terrorists we have to worry about are British and an attack "could happen at any time."
Listen to the full interview above