Richard Dearlove, former head of Britainâ€™s MI6 overseas spying operation, said the security cost of leaving the European Union â€œwould be low,â€ explicitly rejecting Home Secretary Theresa Mayâ€™s argument for staying in the bloc.
Following Tuesdayâ€™s terrorist attacks in Brussels, whether EU membership enhances or harms the safety of British people has become the top issue in the debate about leaving. The U.K. will vote on membership on June 23 and polls suggest the result may be close.
Along with May, Defence Secretary Michael Fallon said this was â€œnot the time to be walking awayâ€ from international groups. Writing in Prospect magazine, Dearlove, who led MI6 between 1999 and 2004, said suggestions that intelligence was shared through the EU are a misunderstanding, and that the nature of the relationships between security forces means information is passed directly from one country to another.
â€œBritain is Europeâ€™s leader in intelligence and security matters and gives much more than it gets in return,â€ Dearlove wrote.
â€œIt is difficult to imagine any of the other EU members ending the relationships they already enjoy with the U.K. The crucial practical business of counter-terrorism and counter-espionage is conducted, even in Europe, through bilateral and very occasionally trilateral relationships.â€
Dearlove said a so-called Brexit would bring â€œtwo potentially important security gains:â€ Control over immigration from the EU, and the ability to dump the European Convention on Human Rights, which he said has hampered efforts to deport
His case was disputed by others working in intelligence and security. Rob Wainwright, director of Europol, the EU police agency, told the BBC that Britain benefits on a â€œdailyâ€ basis from access to shared databases. And David Omand, former director of GCHQ, Britainâ€™s communications interception agency, argued there is no prospect of Britain leaving the human-rights convention even if it does leave the EU. Cooperation is what enhances security, he said.
â€œWhat matters is the value that our relationship to our European partners does bring to our security, especially information to help the management of our border,â€ Omand said in a statement released by the Stronger In group, which is campaigning to stay in the EU.
â€œWe are part of an established information-sharing network with our partners whilst still retaining control of our border. Why jeopardize the flows of information we receive?â€