David Cameron is holding talks with senior intelligence and security officials today in the wake of last week's deadly attacks in Paris that left 17 people dead.
The three perpetrators Said and Cherif Kouachi and Amedy Coulibaly, who had a history of extremism, were shot dead on Friday following an attack on the offices of satirical magazine Charlie Hebdo and two separate sieges.
The prime minister, who travelled to the French capital to join millions of people for a unity march against terrorism, has said that the UK faces a "very similar threat" from fanatical extremism.
Subscribe to The Week
Escape your echo chamber. Get the facts behind the news, plus analysis from multiple perspectives.
In a broadcast interview ahead of the rally, he said: "There's always things to learn and it's always important to look at what happened in France and think through those scenarios and other scenarios like them: how we'd respond, how well prepared we are."
The prime minister said he would be addressing these questions at the security meeting today to ensure that the UK is as prepared as it can be to deal with such a threat.
He added that success would mean investing in security services, as well as "confronting the poisonous narrative of Islamist extremism wherever we find it".
The Tories have suggested they will revive plans for a communications data bill if they can secure an overall majority in May. The bill, dubbed the "snooper's charter", was blocked by the Liberal Democrats.
Cameron has said that rules on interception need to be modernised, but BBC assistant political editor Norman Smith says it is unlikely that any new legislation would be announced in the wake of the Paris attacks.
"The balance of parliamentary opinion at the moment is that we have already given the security services a lot of additional powers and resources," he says.
"Appalling and terrible though Paris was, I don't think that has fundamentally changed that political consensus."
Cameron will also fly to Washington for urgent security talks with US President Barack Obama later this week, while French President Francois Hollande was due to chair a crisis meeting with cabinet ministers on national security today.
Continue reading for free
We hope you're enjoying The Week's refreshingly open-minded journalism.
Subscribed to The Week? Register your account with the same email as your subscription.