Lord Carlile is the former independent reviewer of anti-terror legislation

When reports of the horrific Paris attacks on Friday broke on the news, I was at the wonderful Royal Variety Performance at the Albert Hall in London. The news permeated the audience as people began to receive text messages and tweets on their mobiles. Shocked whispers at that juncture referred to 20 or more dead.

As I began to read the full extent of the horror on my smartphone, a person near me asked something that I am sure was already on everyone’s mind: ‘How safe are we in the UK, in London, here in the Albert Hall?’

This question is haunting the minds of many realistic and good British citizens this weekend.

Yesterday, I saw messages from students asking their parents anxiously about safety.

I noticed that the crowds at the Lord Mayor’s Show in the City of London were reduced, doubtless as a result of anxiety about crowded places.

Prime Minister David Cameron, who chaired an emergency Cobra meeting yesterday to assess UK safety, is plainly concerned about this key issue – how safe are we in the UK?

The carnage unleashed in Paris signalled the arrival of Mumbai- style attacks in Europe.

In that Indian city in 2008, gunmen launched 12 co-ordinated attacks simultaneously, and killed 164 innocent civilians. The Paris attacks have already left nearly 130 dead, with many still critical.

For years, as someone with specialist knowledge of terrorism, I had dreaded this type of attack coming to the West.

I had long been concerned about soft targets – concerts, restaurants, clubs, anywhere with poor to moderate security where people congregate.

I feared this would happen in the UK: I still do. My worst fears were realised in Paris. So how safe are we?

I agree that such spectacular gun attacks may be more difficult here, as it is harder to obtain guns in the UK.

We are not part of the Schengen open borders arrangement: we have checks carried out by a Border Force run with precision by the former Admiral Sir Charles Montgomery.

Fleeing the massacre: A dramatic new video has emerged showing desperate Paris terror attack victims escaping from a theatre where jihadi gunmen slaughtered dozens of concert-goers, with some dragging their bleeding friends along the ground to safety

A terrorist cannot buy a gun in Eastern Europe, and then catch a train to our capital without border checks.

Nevertheless we are severely threatened, some would say at ‘the severe end of severe’.

Terrorists have tried and are determined to launch attacks here, either directed by Islamic State, or inspired by this barbaric group.

I don’t want to go into minute detail, but you can imagine what type of attacks they might be – stabbing sprees, the beheading of a police officer or a member of the public, and 7/7-style bomb attacks.

This is why, now, more than ever, we must let our security services and police get on with the job, and equip them with all the powers that they need. This can be done without any real risk to hallowed freedoms.

I am not arguing for blanket powers for the police and other security agencies to do what they like without oversight, but for speedy confirmation of powers that, responsibly, they have asked for and which they have demonstrated they need.

In order for terrorists to launch any kind of attack – especially one as sophisticated and co-ordinated as the Paris atrocity – they need to communicate.

Terrorists use the internet, especially encrypted apps and software to communicate, to plan attacks and to make contact with their masters in Syria or elsewhere.

The security services urgently need to be able to intercept that level of communication, to disrupt atrocities such as the slaughter that took place in Paris. In Britain, thanks to the vital communications data and interception work that our security services do, a number of recent plots have been foiled even before the alleged terrorists were anywhere near executing them.

A victim under a blanket lays dead outside the Bataclan theatre in Paris where around 100 concert-goers were massacred by jihadi gunmen

Cafe horror: A woman wipes tears from her eyes as she and other survivors help comfort some of the wounded

The Batlaclan violence was part of a string of attacks that is thought to have killed at least 150 on Friday night. Above, an injured man is carried by emergency workers

The Investigatory Powers Bill, which was published in draft form a fortnight ago by Home Secretary Theresa May, gives our spies all the powers they need to fight terrorism in the aftermath of the Snowden leaks, which have shown terrorists ways to hide their electronic footprints.

I and other politicians want this Bill to be expedited, so that rather than becoming law by the end of 2016, which is the plan, it should become law as soon as possible.

These are extraordinary times. The threat from terrorist attacks emanating from Syria is the highest it has ever been, and we cannot wait for another horrific murder like that of Drummer Lee Rigby before we act.

Islamic State is a barbaric group and it poses the greatest threat to our peace and security – even more so than Russia.

We need to take more decisive action against IS in Syria. There is some desire in David Cameron to take action and Michael Fallon, the Defence Secretary, has been very clear about military intervention in the war-torn country.

Now the whole of Parliament needs to be decisive.

The Leader of the Opposition, Jeremy Corbyn, must wake up to his responsibilities. His comments about the killing of Jihadi John – that it would have been preferable to bring him to trial and not kill him – were just absurdly unrealistic, and offensive to many.

The Liberal Democrats are approaching these issues from a civil liberties point of view, and the SNP, who are an important party in Parliament, are all over the place. Its leaders should now tell its MPs that freedom, whether of speech or of action, depends on safety.

A victim is wheeled out of the Bataclan concert hall where Islamic State gunmen mercilessly slaughtered up to 100 fans before blowing themselves up in a series of co-ordinated attacks across the French capital

A woman is comforted as she breaks down outside the Carillon cafe and the Petit Cambodge restaurant where victims were gunned down

The powers sought in relation to communications will strengthen, not weaken, the liberal State.

To tackle Islamic terrorism, we should return to the political cross-party position we had, and to a great extent still have, in dealing with terrorism in Northern Ireland – with plenty of open debate, and yet a consensus to beat this scourge.

Finally, I regret how slow Britain’s Muslim leaders were in condemning the Paris attacks. The Muslim Council of Britain has made a strong statement, but there could have been so much more.

There are some brilliant young imams in the Muslim community, but they are led by tired old clerics, whose mindset is still trapped in South Asia or the Middle East.

Muslim leaders, especially those from the younger generation, need to come out and condemn this attack more forcefully, and they need to make clear that these attacks, and especially the notion of suicide bombings, are a profound heresy in Islam.

They need to say loudly that terrorism does not lead anyone to paradise, but rather to hell itself.

This is what moderate Muslim clerics from around the world tell me, and this is what Islamic clerics here need to say.

Only then can this vicious narrative peddled by IS be defeated.