UK more vulnerable to terrorists in the event of EU exit

London: British Prime Minister David Cameron on Tuesday warned that Islamic State (ISIS) terrorists would be happy if Britain was to vote to leave the European Union (EU) in the crucial June 23 referendum.

Cameron, who was addressing a World Economic Forum event in London, highlighted on the negative impact of Brexit, which would be welcomed only by Russian President Vladimir Putin and Abu Bakr al-Baghdadi, the chief of ISIS.

"Who would be happy if we left? Putin might be happy. I suspect al-Bagdadi might be happy," he said.

His latest comments, alluding to making the UK more vulnerable to terrorists in the event of an EU exit, will be described as scaremongering by the Leave camp, which says Brexit would give the UK greater control over its borders.

The Cameron-led Remain campaign maintains that the UK already has the power to check all passports, with a pan-European security network providing additional security.

Cameron also vowed that the referendum will be a "once in a lifetime" event, rubbishing statements by some Leave campaigners raising the prospect of another referendum in the future.

"I'm absolutely clear that the referendum is the referendum. It is a once in a generation, once in a lifetime opportunity. The result determines the outcome - if we vote to stay, we stay, and that's it. If we vote to leave, we leave, and that's it. We can't have 'never-endums'," he said.

He was responding to comments made by UK Independence Party (UKIP) leader Nigel Farage that there could be strong demand for a re-run of the EU referendum if the Remain camp wins by a narrow margin on June 23.

"In a 52-48 referendum this would be unfinished business by a long way. If the Remain campaign win two-thirds to one-third that ends it," he said.

The opinion polls are running neck-and-neck currently, with both camps at a nearly 50-50 vote. The campaigning by both sides will intensify in the coming weeks in an attempt to swing any undecided votes.