Information sharing that is crucial to keeping London safe could become “clunkier, clumsier and more expensive” after Britain leaves the EU.

Earlier today the London Assembly police and crime committee met with the commissioner of the Metropolitan Police, Cressida Dick and Sadiq Khan’s second in command for policing Sophie Linden.

Liberal Democrat London Assembly member Caroline Pidgeon questioned the commissioner over the current and future challenges to counter terrorism and policing in the capital.

Ms Dick said: “We will need continued and sustained investment.”

The commissioner also told members of the committee that since the Westminster attack last year there have been 441 terrorism related arrests nationally and that recently 13 lethal Islamist attacks have been foiled in London.

She also said that police were seeing more right-wing extremist plots and that four had recently been “disrupted”.

But Labour assembly member Andrew Dismore raised concerns that security could weaken after Brexit.

Ms Dick told him: “We are not part of the Government negotiation and what we have done is laid out what we think it important to them and what we need.

“In terms of crime we are big contributors to Interpol and if we are not able to access the same systems as we are now it will be clunkier, clumsier and more expensive.”

These systems include joint investigations and information sharing databases.

Government ministers have proposed a security treaty under which criminal suspects could be speedily extradited between states, as they are now under the European Arrest Warrant system.

The government is currently negotiating with the EU to ensure continued access to Europol and a range of law enforcement databases.

Ms Linden, the deputy mayor for policing and crime added: The thought of not being able to use this information sharing is incredibly worry and myself and the mayor have been to see David Davis to lobby him around these issues.

“Security is real threat around Brexit and unless we get a good deal police will have to phone colleagues overseas each time they want information.”