Ellen MacArthur's lucky she didn't get 50 yards from British waters and find Charles Clarke there, waiting on a boat with immigration officials, announcing: "You can't come in this country, love, we're full up."

From now to the election, Labour and the Tories will carry on competing for who can look toughest on immigration, as if they're playing a party game. The last of these contests was won by Blair. The Tories said they'd keep all asylum-seekers in camps. So Labour said they'd cut all their benefits; the Tories came back with not letting them apply for jobs; then Blair said he'd take away their kids, at which point Howard put his hands up and said: "You're too good for me mate, I can't keep up with that."

In response to the Tories' "quota", the Government has proposed that potential immigrants should be awarded points, to work out whether they'll be an "economic benefit" to the country, and if they don't score enough they won't be allowed in. It would be fairer if they had to parade their skills before a panel of Sharon Osbourne, Geri Halliwell and Simon Cowell. Most of them will get Cowell snarling: "Call that carpentry? It's pathetic. Get back to Burma, you deserve to be tortured." But a lucky few would go through to a grand "Immigrant Idol" final, ending with a viewers' poll to select the 12 that can stay.

Because how do they know who's going to be an "economic benefit"? Perhaps they're planning to get one of Cherie Blair's mates to stand at the immigration queue reading everyone's palm. Then they can make recommendations for deportation, based on who's got a strong burden line.

The plan seems to be that we'll let someone in only if they're a doctor, or can perform a trade we need. So maybe we should start placing orders. For example, at the moment there's a shortage of tradesmen in London. So we should write to the Indonesian government, asking: "Would it be possible to torture around 200 plumbers, so that they might apply for asylum in our country where they would be able to mend our drains, and provide economic benefits."

We could probably be even more careful. A Sri Lankan dentist may be a benefit while he's working, but during the weekend he'll borrow books from our libraries and cross the road at our pedestrian crossings and so on, proving an utter burden. So why not let him stay while he's working, then deport him every Friday night until he's willing to be a benefit again? After all, what are we - mugs?

It could be argued that our society is enriched by immigrants, even when they're not economic assets. But apparently, that's wrong. Next time you walk past a vibrant Pakistani market selling a flamboyant array of textiles, spices and mangoes, remember the real question is whether it could yield greater fiscal potential if it was turned into office space.

Several countries may wish they'd been able to apply similar rules to the British, when we were keen on settling in foreign lands. I bet India would have loved a rule that went: "You will be deemed liable to deportation if you make yourselves an economic burden by, a) claiming milk tokens you're not entitled to, or b) destroying our native cotton industry. Furthermore, just one more massacre at a temple and you're off."

But it's doubtful whether any of this is about economics at all. In one paper yesterday, there was a huge headline complaining: "Workshy British force boss to recruit Poles." It turns out that a box-packing business can't recruit staff, so they've had to hire 400 Poles. But isn't Poland one of those countries from which hordes of migrants flock to lap up our over-generous benefits? But now it's apparently the Poles who want to work and the British who are lazy. So surely the only economics that makes sense now is to kick out all the English. If we're to save this overcrowded island, there can be no room for the hordes of us English, busting our public services that are already breaking at the seams. We must be prepared to be tough and replace the entire population with Poles.

There's no logic to the ranting about asylum-seekers, yet as with crime, every time the Tories scream, Labour follows. So part of Blair's reply to the Tory proposals was: "The Government has legislated several times on the issue - each time toughening up - and is prepared to do so again." By the time of the official election campaign, Labour's broadcasts will start with film of Blair cutting his finger and pressing the blood onto a deportation order. Then he'll take a deep breath and whisper: "Man hath no greater thrill than to vanquish an economic burden."

It makes you realise the Tories don't want to win the election. They don't need to, as they run the country anyway, and don't have to bother with the paperwork. It's as if they've got a servant to do everything for them. In the New Labour headquarters a bell goes, and a voice says: "Chuck out another batch of immigrants would you, old boy." Then Labour runs around doing it while the Tories are off to lunch. You watch. If they look like they might be catching up, they'll bring back Iain Duncan Smith to make sure.