Brexit is set to make the UK a safer place for criminals, the police chief in charge of preparations has warned.

Deputy assistant commissioner Richard Martin said that the loss of EU tools and databases could create a public safety risk by allowing suspects to abscond and making it harder to extradite foreign nationals.

Police officers forced to use outdated conventions would spend hours in stations negotiating red tape rather than being on the streets, he told journalists, and the change will cost forces at least £20m extra a year.

“Criminals are entrepreneurs of crime and I’m sure they’re looking at their business model,” Mr Martin told journalists. “If there’s a gap to exploit, I’m sure they would.”

Speaking at the new International Crime Coordination Centre in London, where officials are working on contingencies for a potential no-deal Brexit, the senior officer said all current alternatives to EU systems were “more bureaucratic and slower”.

Police separate clashing Brexit protesters outside Parliament Show all 11 1 /11 Police separate clashing Brexit protesters outside Parliament Police separate clashing Brexit protesters outside Parliament Anti-Brexit protester Steve Bray (left) and a pro-Brexit protester argue as they demonstrate outside the Houses of Parliament Getty Images Police separate clashing Brexit protesters outside Parliament A pro-Brexit protester argues Getty Images Police separate clashing Brexit protesters outside Parliament Police surround the pro-Brexit protester after he confronted Steve Bray, a pro-European protester Getty Images Police separate clashing Brexit protesters outside Parliament A leave supporter is spoken to by a police officer as he argues with a remain supporter, Steve Bray, outside Parliament PA Police separate clashing Brexit protesters outside Parliament MPs in Parliament are to vote on Theresa May's Brexit deal next week after her December vote was called off in the face of a major defeat Getty Images Police separate clashing Brexit protesters outside Parliament A leave supporter is spoken to by a police officer PA Police separate clashing Brexit protesters outside Parliament Police look on as anti-Brexit protesters demonstrate outside the Houses of Parliament. Getty Images Police separate clashing Brexit protesters outside Parliament Police hold back a leave supporter PA Police separate clashing Brexit protesters outside Parliament A police officer speaks with anti-Brexit protester Steve Bray Getty Images Police separate clashing Brexit protesters outside Parliament Police surround a pro-Brexit protester after he confronted a pro-European protester Getty Images Police separate clashing Brexit protesters outside Parliament Conservative MP David Davies, wearing a gopro camera, speaks to anti-Brexit protester Steve Bray Getty Images

Police chiefs are currently briefing all British forces “on the basis that we don’t get a deal and lose all powers”, and checking their ability to use contingencies.

“Because processes have been automated for such a long time, officers will be using EU systems without realising,” Mr Martin said.

“Some forces need some assistance to get us into a place where they’re fully ready.”

He added that the need for officers to search multiple databases and channel requests through bilaterals would “have an impact on frontline policing” at a time when forces are already stretched by years of budget cuts and rising violent crime.

“If something takes two or three times as long, that will be another two or three hours you’re not on the streets,” Mr Martin warned.

With no agreement accepted by parliament, on 29 March the UK is set to be kicked out of the European Arrest Warrant (EAW), Europol, Schengen Information System (SIS II), European Criminal Records Information System (Ecris) and other frameworks.

SIS II is currently checked 539 million times a year by British police officers because their equipment automatically searches the international database of criminals and terrorists at the same time as the Police National Computer.

If lost, they will have to make a separate search on Interpol’s I-24/7 database, but Mr Martin said EU countries do not routinely upload information or check it.

The UK currently makes an “absolutely miniscule” number of arrests based on Interpol red “wanted” notices, and unlike EU systems they do not give police the power to immediately request suspects.

“If an officer checks I-24/7 and it comes back with a red notice, we would then have to go to a magistrates’ court to get a warrant to arrest that person,” Mr Martin explained.

“We would not be able to detain the person in front of us.”

If there was no other legal basis on which a suspect could be detained, police would have to release them and then “find them again” when a judge had granted permission.

Mr Martin said the Ministry of Justice was examining the potential for a huge increase in demand at magistrates’ courts as a result of the system, following years of closures to make savings.

He said there was also concern about a loss of intelligence on foreign suspects’ past criminal records, which are used to make a decision on the risk they pose, and whether they should be bailed.

Theresa May confident Brexit will be delivered on March 29

EU countries currently reply to requests through Ecris in an average of six days, which will rise to a minimum of 66 days if officials have to fall back on a 1959 convention.

“My fear is if we don’t get information back in a timely fashion there is a real risk criminals could abscond,” Mr Martin said. “Those criminal records are so crucial.”

If the UK loses access to the EAW system, it will rely on bilateral agreements to extradite suspects for trial or deport criminals to their home countries.

Before EU-wide arrest warrants were brought in, the UK only extradited up to 60 EU citizens a year – now the figure ranges between 1,800 and 2,000.

And while a suspect can be arrested and transferred to Britain within days under the EAW, as with the case of Stephen Lawrence murder suspect Jamie Acourt, the same process outside the system takes far longer.

Some countries, including Germany, also have laws against extraditing their citizens outside the EU.

Theresa May’s withdrawal agreement, which was rejected by parliament, extended UK access to all systems until the end of a transition period, when officials will negotiate on how to keep the tools.

A separate political declaration with the EU outlined a commitment to capabilities “that, in so far as is technically and legally possible, approximate those enabled by relevant Union mechanisms”.

Mr Martin said British and EU law enforcement bodies “would like to keep the powers we have” in the interests of mutual security.

But there are concerns that data rules and resourcing issues could bar some intelligence sharing, and political decisions are out of the police’s hands.