Former PM Gordon Brown warned that leaving the EU would turn Britain into Europe's North Korea . Britain would turn into the European North Korea if it left the EU, Gordon Brown has claimed. In a bizarre warning ahead of a speech to the Commons tomorrow, the former Prime Minister said the UK would be 'left out in the cold with few friends [and] no influence' like the regime in Pyongyang. He rejects claims that Britain could succeed on its own by becoming an open, trading nation like Switzerland or Hong Kong. But the warning that Britain would fall into North Korean isolationism is likely to spark ridicule. A report commissioned by Boris Johnson last year said leaving the EU was 'definitely a viable option' for the UK. Mr Johnson's chief economic adviser Gerard Lyons said the best option was to stay in a reformed European Union – but if that couldn't be achieved exit was better for the economy than the status quo. But in a startling intervention ahead of tomorrow's House of Commons debate on the EU, Mr Brown said: 'We must tell the truth about the 3 million jobs, 25,000 companies, £200billion of annual exports and the £450billion of inward investment linked to Europe.' He said leaving the EU but staying in a free-trade area could leave us 'subject to EU rules, but denied a vote in shaping them'. The former Labour leader, who is stepping down as an MP in May, also dismissed the 'Hong Kong option – leaving Europe to join the world. He said this was 'really the North Korea option – out in the cold with few friends, no influence, little new trade and even less new investment'. In a bizarre warning ahead of a speech to the Commons tomorrow, former Prime Minister Gordon Brown said the UK would be 'left out in the cold with few friends [and] no influence' like North Korea under Kim Jong-un . Mr Brown, writing in the Guardian, said Britain should not contemplate exit when it was on course to overtake Germany as the EU's largest economy. He said: 'It would be sheer defeatism to cast ourselves, as sceptics do, as helpless victim, impotent bystanders unable to influence events. 'Our destiny is not a bit player on someone else's stage, or a spectator hectoring from the wings, but always setting the agenda, bringing people together, and championing change.' He added: 'Being half-in half-out, a Britain that is semi-detached and disengaged – the Britain of the empty chair even when we are in the room – has made us weaker than ever: irrelevant on Greece, fringe player on climate change, mere spectator in the debate that could have shaped a European pro-growth policy, marginal on Ukraine, with ministers sounding ludicrous as simultaneously they say: 'Russia must be confronted with a more united Europe', and: 'By the way, we are thinking of leaving.'
Former PM rejects claim Britain could succeed on its own outside the EU . Dismissed suggestion UK could be an open, trading nation like Hong Kong . He said this was 'really the North Korea option' with Britain isolated .