The Mayor of London has claimed that criminals want a no-deal Brexit, in a series of controversial comments at Mayor’s Question Time.

Sadiq Khan yesterday said leaving the European Union without a deal would weaken Britain’s ability to police across borders.

But critics dismissed his statements as “shameless” and “singularly unimpressive”.

The Mayor said a no-deal exit from the EU would slow down extraditions from European countries, and limit police access to information shared internationally – making it easier for criminals to operate.

He said: “If you’re a criminal you want there to be no deal Brexit – you don’t want the authorities to trace and track you.

“That’s why I think it’s really important for us to wake up on the consequences of us leaving the EU, but even worse the consequences of us leaving without a deal."

Mr Khan also told the meeting he was worried that businesses in London were still not prepared for a no-deal exit – particularly small firms without the resources to plan ahead.

He called again for the Government to revoke Article 50 and halt Brexit to protect jobs in the capital.

But Conservative assembly member Keith Prince, speaking on Twitter, described the Mayor as “shameless”.

Referring to Mr Khan’s comments on criminals, he said: “In a crowded field this may be the most ridiculous thing he's ever said at Mayor's Question Time.”

The Brexit Alliance Group said they were “singularly unimpressed” with the Mayor's claims, and fundamentally opposed his position on Brexit and his desire to revoke Article 50.