7/7 London bombings anniversary: Britons who want to fight for Isis should be 'put on charter flight to Syria'

Ten years on from the 7/7 bombings, the UK terror threat level has risen and a growing number of citizens want to defect to extremist territories abroad

These young British men featured in an Isis video urging Islamists in the West to join them in Iraq and Syria. (Reuters) (Reuters)

One of the UK's former leading chiefs on counter-terrorism has said would-be jihadis should be allowed to surrender their British passports and travel to join extremist groups.

Robert Quick, the former assistant commissioner at Scotland Yard said Britons who wish to go to Isis-controlled areas in Iraq and Syria should be allowed to.

"If they want to go, you have to ask the question, are we better off, if they surrender their passports and go? It’s better than them festering away here", the former head of special operations from 2008-09 told the Guardian.

Police take part in a counter-terror exercise drill in central London on 30 June (Ben Stansall/AFP)

"Should we say we’ll lay on charter flights to Syria; turn up with your passport and if you are over 18, if this is the life you want, then go?", Mr Quick asked.

Any members of the public wishing to join extremist groups abroad would forfeit their passports and never be allowed to return to Britain, he said.

Currently counter-terror forces are working to stop British people from defecting to Isis territories although as many as 1,000 people are estimated to have done so.

Ten years on today from the 2005 terrorist attacks in London, which saw 52 people murdered in four separate bombings, Britain is at an even higher terror threat level.

The national terror threat level is now standing at "severe", meaning an attack is "highly likely", according to experts at the Royal United Services Institute (RUSI).

Margaret Gilmore, a senior associate fellow specialising in national security at RUSI and a former BBC home affairs correspondent at the time of the attack, told The Independent that the threat is greater because it is now "more diverse".

"Isis has emerged as an organised, powerful and barbaric group which has developed the ability to lure support among extremists from across the globe."

Following the terror attacks on British tourists in Tunisia, last week, British security forces held two days of large-scale training exercises in London, around the disused Aldwych tube station, focussing on what might happen if a lone gunman or bomber targeted the UK.

Andrew Parker, the director general of MI5, said in a statement marking the 7/7 anniversary: "We had always known - and said publicly - we simply can’t find and stop every terrorist plot. We could not have prevented 7/7."

Although inquests into the police’s response to the 7/7 bombings raised exposed some of the failings of the emergency response, Dr Afzal Ashraf, a consultant fellow at the RUSI said changes in practice since 2005 mean "there’s no doubt that our security services and our police are very much better prepared than they were 10 years ago".