Barack Obama: The world needs a united EU

US president Barack Obama has delivered an impassioned defence of the European Union, warning that America and the world need a “united” Europe.

In comments which are likely be seen as a further plea for a Remain vote in Britain’s June 23 referendum, Mr Obama hailed the EU as “one of the greatest political and economic achievements of modern times” and cautioned individual states against rebuilding barriers which existed in the 20th century.

Mr Obama’s intervention, in a speech in Germany, came as Brexit’s biggest hitters sought to seize back the referendum initiative by putting immigration at the top of the agenda.

Britisn justice secretary Michael Gove warned the UK faces a migration “free-for-all” unless it breaks away from Brussels as the ‘Leave’ camp moved to exploit an admission from the Government that EU free movement of labour rules make it harder to curb immigration.

However, Mr Obama warned of the dangers of an “increasing intolerance” in politics which promoted an “us versus them” mentality towards migrants.

Speaking at the start of the G5 summit in Hanover, where he will discuss security threats with British prime minister David Cameron, German chancellor Angela Merkel, French president Francois Hollande, and Italian prime minister Matteo Renzi, Mr Obama acknowledged that anxieties over globalisation, terrorism, and immigration were “real and legitimate”.

“All these challenges have led some to question whether European integration can long endure, whether you might be better off separating off, redrawing some of the barriers and the walls between nations that existed in the 20th century,” he said.

“If a unified, peaceful, liberal, pluralistic, free-market Europe begins to doubt itself, begins to question the progress that’s been made over the last several decades, then we can’t expect the progress that is just now taking hold in many places around the world will continue.

“Instead, we will be empowering those who argue that democracy can’t work, that intolerance and tribalism and organising ourselves along ethnic lines and authoritarianism and restrictions on the press - that those are the things that the challenges of today demand.

“I’ve come here today to the heart of Europe to say that the United States and the entire world needs a strong and prosperous and united Europe.”

Mr Obama said he understood dealing with Brussels could be “frustrating” and slow down decision-making.

However, he said the union had brought peace among its members and insisted that a strong, united Europe was vital for global security and prosperity.

“Remember that every member of your union is a democracy. That’s not an accident.

“Remember that no EU country has raised arms against another. That’s not an accident.”

Mr Obama said a “strong united” Europe remains a “necessity for all of us”.

“It’s a necessity for the United States because Europe’s security and prosperity is inherently indivisible from our own,” he added.

“A strong united Europe is a necessity for the world because an integrated Europe remains vital to our international order.”

Ms Obama said Islamic State was the “most urgent threat” to Western nations and warned the EU it “could do more” through air strikes, military trainers and economic assistance to stabilise Iraq.

Urging all EU countries to meet the Nato target of spending 2% of national income on defence, he added: “Sometimes Europe has been complacent its own defence.”

London mayor Boris Johnson came out fighting after being condemned over his highly personalised attacks on Mr Obama during the president’s two-day visit to the UK.

And former cabinet minister Iain Duncan Smith said Mr Obama was wrong to suggest that the UK would be at the “back of the queue” for a trade deal, claiming there were many politicians in Washington eager for an agreement with post-Brexit Britain.

Mr Johnson turned his fire on Mr Cameron with a scathing assault accusing him of achieving “two-thirds of diddly squat” in negotiations with Brussels for a special deal for Britain on immigration and other key demands.

But he sidestepped questions about the row he caused by referring to Mr Obama’s “part-Kenyan” heritage.

Asked about accusations of “dog-whistle racism”, Mr Johnson told Sky News: “Look, I think the crucial thing is what kind of future is there for this country outside the EU.

“We’ve been told we have to go to the back of the queue. That seems to me to be ridiculous when you consider the real reason we haven’t been able to do a free trade deal with the United States in the last 43 years is we are part of the EU.”

In his Daily Telegraph column, Mr Johnson warned the ‘Remain’ side not to “crow too soon” that the ‘Leave’ side had been “bombed into submission”.