David Miliband
David Miliband addresses the Institute of Directors convention in LondonToby Melville/Reuters

The European refugee crisis supports the case for the UK remaining inside the EU and improving the 28-nation bloc, according to David Miliband. The International Rescue Committee (IRC) chief warned that the last thing needed would be a fragmented EU, as the humanitarian crisis continues.

"The refugee crisis makes the case for an improved EU, the last thing we need is a fragmented EU. I would argue that the refugee crisis is not an outlier in requiring an improved and co-ordinated EU," Miliband said.

"I think about European or British relations with Russia, that's another area where a more integrated energy policy would actually be a strength – not just for Britain, but the EU."

The former Labour foreign secretary, who was speaking at the Institute of Directors (IoD) annual convention in London on 6 October, also argued that more "cohesion" was needed and that regional governments like the EU would become increasingly important.

"I am actually a great believer that we win our arguments around the table rather than out of the room," Miliband said. "In the modern world are you stronger or weaker in alliance with your neighbours or separate from them? All that I see, given the weakness of global governance, is more and more regions are seeking to come together."

He added: "My belief is, pivoting off the refugee crisis, there's a case for an improved EU and I don't see any cause for believing that Britain could somehow be a kind of Singapore of the North Atlantic that's going to live outside its European continent of which it is a neighbour."

The former Labour leadership contender said the run-up to the EU referendum, which David Cameron has promised to hold before the end of 2017, would be an opportunity for debate but also a "time for clarification and myth-busting".

Miliband's comments come after the current foreign secretary, Philip Hammond, claimed the refugee crisis would help David Cameron with his renegotiation with Brussels as the issue would focus the minds of EU leaders who may have opposed the prime minister's proposed immigration reforms.

"The fact that Europe is facing the challenge... of migration flows within Europe of newly arrived migrants, is perhaps focusing the attention of some people, in a way that hadn't been focused before, about the challenges that migration at scale presents. And that's been our argument all along," he told Reuters on 23 September.

Cameron is expected to campaign to keep the UK within the EU after his renegotiation, but the latest opinion poll from YouGov showed that the British electorate are split over the historic vote. The survey, of more than 2,700 respondents between 17 and 22 September, put Leave on 41% and Remain on 38%.

The topic of immigration will likely feature heavily over the campaign and a recent survey from Ipsos MORI showed that the issue has become the top concern in the electorate's mind. The poll, conducted between 4 and 17 September, found immigration is now the most important issue across all ages, social grades, and party supporters, from three quarters (76%) of Conservative voters to half (49%) of Labour voters.