Late November 2014 was not the busiest time for news.

The most striking images, in the BBC’s week in pictures, included Lewis Hamilton clutching his girlfriend Nicole Sherzinger after winning his second F1 world championship and a Snoopy balloon floating down Sixth Avenue during a Thanksgiving parade.

But amid it all was a speech by the prime minister which we ought to remember. On 27 November, David Cameron declared that he would “rule nothing out” if he failed to achieve significant reforms in his renegotiation with the EU.

It is difficult now to imagine that the prime minister was hinting that he would be prepared to campaign for Britain to leave the EU. He is now the figurehead of a campaign that is rolling out one apocalyptic warning after another about the potential impact of Brexit.

The Tory leader has even won the strong support of two presidents – Barack Obama (sending us to the “back of the queue” on trade) and François Hollande (ready to tear up a bilateral agreement that would push the British border from Calais to Kent).

There are, of course, sensible counter arguments. Chris Grayling reminds us that we do not have a trade deal with the US now, but everything seems okay, and French and British cabinet members all seem to agree that Le Touquet agreement would stay because it is in both country’s interests.

As for Boris Johnson, he was a man who was not quite sure which way to go, a politician who previously had positive things to say about the EU. By last week, the London mayor was talking about the “tragedy” of a union that he argued was stifling democracy and had stripped Britain of its ability to control its borders and its trade policy.

Can you tell there is an election on?

Perhaps a high-stakes referendum, with two irreversible outcomes, was never likely to result in a calm or nuanced debate.

Both sides will go to any lengths to secure the victory they want. As one source on the leave side puts it: “David Cameron and George Osborne are fighting for their political lives.” Johnson, meanwhile, is battling for a political future.

And what has changed after Obama’s intervention is that the two sides are thinking harder than ever about strategy and positioning, with the clearest division yet between an argument about the economy or one on immigration.

The remain side have been accused of scaremongering, but after support from the International Monetary Fund and the Institute of Fiscal Studies, the publication of a weighty Treasury report and the backing of the leader of the free world, they will rightly feel on the front foot when it comes to the economy.



So what can the outers do? “We need to neutralise them on the economy,” says one source, meaning they talk about business, they rebut Obama and they question the Treasury figures. But they also accept that they cannot possibly win on the issue of finances.

Which is why this week’s fightback is not about the money, but immigration: about free movement, about the accession of Turkey and about the impact it all has on public services such as the NHS.

The message is of an EU deal in which the UK “puts in a lot of money and gets out lots of immigration”.

And as for the intervention of Obama, Hollande, business leaders and European diplomats? “It is a David v Goliath fight. We are up for that,” says Paul Stephenson, spokesman for Vote Leave. “The EU is good for people in power, including multinational corporations and world leaders. That doesn’t mean it is good for British people.”

Those backing the Brexit know that they still have the Eurosceptic sentiment of the public to tap into and they think (I suspect correctly) that people are at least a little sceptical of overly dramatic warnings from overseas.

But they are also going to make this personal about the prime minister and that is why, alongside warnings around immigration, Johnson this week reminded us of that EU renegotiation.

After all, leave campaigners remember what Cameron said in November 2014 and much earlier at his coveted Bloomberg speech in early 2013. Back then, he warned that the EU was in flux and that the status quo was not acceptable.

They will remind voters of that repeatedly between now and 23 June and it will be for Cameron to try to persuade the public that the out campaign have got it wrong.