The polls suggest that the race is tightening, and there's a few jitters in the Remain camp, not least in Downing Street.

Here with me is Philip Stephens, Chief Political Commentator of the Financial Times.

Philip, how do you see it? Is it that tight?

Well, all polls have to come with a very big health warning,

we saw last year with the General Election here how they can all get it wrong.

That said, if you talked to people in the Prime Minister's Remain camp, "Let's stay in Europe" camp,

two weeks ago, cheery "we're gonna do it", if not close there, comfortable.

Last night, talking to a bunch of the people at the heart of the campaign, we're nervous, really nervous.

Not quite panicked, but very, very nervous.

So what may have gone wrong?

Well, wherever the polls were two weeks ago, the feeling is they have shifted to the Leave campaign over the past ten days.

The view is that immigration, which the Leave campaign has pretty ruthlessly exploited with some mendacious claims

about the numbers of Turkish immigrants that might come to Britain in the next several years,

the feeling is that that has caught the, if you like the emotions of those groups, the people that Trump is appealing to in the U.S.,

who feel that they've been left on the sidelines by globalization.

And drowned out the message that the Remain camp felt really would resonate, which is the economic costs of withdrawal.

Yes, and I think it still is a battle between economics and if you like, emotion, identity, and these other aspects of policy the Remain campaign is gonna have to sit on.

Look, you may feel bad, you may not like Brussels, you may not like the immigration,

but do you really want to jeopardize the country's prosperity and your own incomes.

And the Leave campaign is gonna push harder and harder I think, on the immigration question

and say look, you're going to be swamped by immigrants if this goes on.

Of course what's extraordinary is that David Cameron, the Conservative Prime Minister,

is sharing the platform with key Labour figures, not least Sadiq Khan, recently elected, the first Muslim mayor of London.

Yeah I think there are two big political trends at work here.

The first is the sort of fragmentation of politics, which we've seen over the past several years,

the two big parties no longer have the iron grip on politics that they used to have.

And the second is really a battle between Roundheads and Cavaliers.

Who's the Roundheads?

The Roundheads are the Leave campaign in the sense in the Tory Party, the people who want to overturn.

They're attacking the elites, the sort of public school educated people around David Cameron.

And of course you see the same in the Labour Party, where Jeremy Corbyn, the leader who mounted effectively a sort of coup led by the activists last year,

They're trying to do the (same), they're pushing back against the Labour establishment.

So what you're seeing is the two establishments, the old Labour establishment and the Tory establishment, pulling together in favor of Remain,

while the, if you like the Roundheads in both parties who've joined together in favor of Leave.

Philip, I'm not going to ask you, even with all your experience, what do you think is gonna happen next week in the referendum,

but I will ask you this: Did David Cameron make a big mistake in calling for a referendum?

He made a terrible mistake. And if it's a Leave vote, he will go down in history as the Prime Minister who made the biggest peace time,if you like, mistake in post-war history.

As for the result, I think one can say one thing: if the normal rules of politics still apply, we will vote to remain.

If the rules of politics have been completely overturned, we will vote Leave and America should start thinking about a Donald Trump presidency.

Philip Stephens, thank you very much.