Politicians who recommend leaving the European Union risk making the country more vulnerable to terrorism, Ed Miliband has suggested during a Q&A in Stevenage.
The Labour leader, who was in Paris yesterday to show solidarity after the Charlie Hebdo attacks, said cross-border co-operation over security was crucial.
Speaking at an event with voters in Stevenage, Mr Miliband reiterated that he wanted the UK to stay in the EU.
"Think about terrorism and counter-terrorism. We are much better working across borders to do that," he said.
"Think about our economy... I just think we are much, much better working within the EU than not."
Asked afterwards whether Mr Miliband thought the Paris attacks had strengthened the case for staying in the union, a senior Labour source said: "It's certainly his belief that security is one of the issues where working across the EU shows its obvious benefits.
"We all remember from 7/7 that the European arrest warrant (EAW) played a vital role in bringing those suspects back to Britain. The EAW has been a very useful tool in dealing with security issues since it was introduced."
Pressed on whether that meant politicians who wanted Britain to leave the EU were endangering people, the source said: "I wouldn't back away from that interpretation.
"I think security is an important part of what the EU does."
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