Barack Obama delivers blunt warning on Brexit fallout

When Barack Obama last intervened in a British referendum in June 2014, it was to suggest in 2014 that the UK would be stronger if Scotland remained part of it. It was little more, however, than an off-the-cuff remark during a press conference in Brussels and although his meaning was clear, it was expressed in oblique, diplomatic language.

The US president showed no such delicacy this time, offering instead a full-throated endorsement of the Remain side in the European Union referendum and citing the "tens of thousands of Americans who rest in Europe's cemeteries" in support of his right to do so. The president argued the case for Britain's continued EU membership with eloquence and warned of the consequences of Brexit with a bluntness that surprised most British observers.

His warning that Britain outside the EU would be at the back of the queue in negotiating a bilateral trade deal with the US undermines one of the most important claims made by Leave campaigners. They have long maintained that Britain’s “special relationship” with the US would ensure that Washington would agree a new trade deal after Brexit with a minimum of delay or difficulty.

Obama left British voters in no doubt that the US would continue to cherish Britain’s friendship but would follow its own economic interests by prioritising the negotiation of a transatlantic trade deal with the EU and other big trading blocs. Britain could probably expect to reach a bilateral trade deal at some stage in the future but it was “not going to happen any time soon”.

Obama’s intervention crowned a disastrous first week of the official referendum campaign for the Leave side, reflected in six successive polls showing gains for the Remain campaign. The Treasury’s 200- page report on the economic consequences of leaving, which predicted that it could cost British households an average of £4,300 (€5,500) a year, left Leave campaigners struggling for an effective response.

Justice secretary Michael Gove's suggestion that Britain could model its post-Brexit relationship with the EU on that of Albania did little to reassure wavering voters. And Boris Johnson's reference to Obama's Kenyan ancestry, repeated by Nigel Farage, will reinforce the impression of the Leave campaign as backward- looking and a little unsavoury.

With nine weeks to go until the referendum, the Remain campaign is growing in confidence while the Leave campaign looks and sounds increasingly like the losing side. The bookies have shortened the odds on a victory for Remain and Ladbrokes said on Friday that 90 per cent of the bets placed since Obama touched down in London were in favour of Britain staying in the EU.