The choppers are out in force, with aerial pics of the Brown motorcade making the one-mile drive back from Buckingham Palace. My former colleagues at Sky News are in "split-screen" mode, with David Cameron on one half, gesticulating and pontificating, and a locked-off shot of a solitary policeman standing outside 10 Downing Street.

So what's the mood inside the bunker? A Brown aide tells me that the PM has a spring in his step. "He's at his best when faced with a tough challenge but he knows he has a plan, so he's fine," says the aide.

And I can believe it. I doubt that the Prime Minister will be punching the back of the front seat of his Jaguar this morning. Not if he's got a copy of the Guardian inside the car with him. The paper's latest ICM poll shows the Tory lead over Labour cut to 4 points for the first time in almost two years -- a lead that, if replicated on 6 May, would leave Labour as the largest single party in the House of Commons.

The Guardian's Julian Glover writes:

On a uniform national swing, these figures could leave Labour 30 seats short of an overall majority. Even if the Tories perform better than average in marginal seats -- as most people expect -- David Cameron would struggle to establish a secure parliamentary basis for power.

Amazing, eh? Who'd have predicted it? Not the great and the good of the anti-Brown lobby or commentariat. And certainly not the arch-critic of all things Brown, John Rentoul of the Independent on Sunday. Only a few weeks ago, John was telling me he had no doubt in his mind that Cameron's Conservatives would win a comfortable, double-digit parliamentary majority. This morning, according to a Paul Waugh tweet, John said:

Nobody, certainly not me, expected Gordon Brown to be in the position he is today.

Not quite. For the last time (I promise!), let me refer you all to the rather prescient column that James Macintyre and I wrote for the NS in June, in the wake of Labour's disastrous performance in the Euro elections, in which we referred to the "Tories' precarious electoral position" and concluded:

If . . . the Brown government can concentrate the country's attention on public services and public spending, Labour may well still stand a fighting chance of a hung parliament at next year's general election.

It's a suggestion, a prediction, that James and I have long stood by. Bring on 6 May!

UPDATE: Before I'm denounced by Tory trolls "below the line" as a "Labour spin doctor", let me apologise for failing to acknowledge above that there is, in fact, another reputable poll out today -- by YouGov for the Sun -- which tells a somewhat different story. The YouGov survey shows the Tories have reopened a 10-point lead over Labour -- which is, of course, the margin they need to maintain in order to win an overall majority next month.

So is the ICM poll just a "rogue", as some Tory sympathisers have suggested? Who knows? Don't forget: as a wise man once said, rogue polls tend to be polls you don't like. And even the YouGov survey shows an increase in the Labour share (from 29 to 31 per cent). So I still think there's reason for Brown, and Labour supporters, to be cheerful this morning.