'The suburbs are being painted red", Labour's John McTernan tweeted at the height of post-poll spin frenzy on Friday.

He meant that Labour was holding off Ukip and the Conservatives in the English metropolis, gaining Hammersmith and Fulham and various other stops on the Tube. Mind you, Ukip had taken the precaution of not standing in most of these suburbs - as one of their number, Suzanne Evans, said with disarming honesty, "media-savvy, well-educated people" don't vote Ukip.

The Kippers are still largely an out-of-London phenomenon, but that doesn't make them any less dangerous. Nigel Farage's candidates were taking 47% of the vote in solid Labour areas such as Rotherham. They took a huge swathe of seats in Essex, including Basildon - home of Essex man, the aspiring working-class voter who turned Tory in the 1980s in admiration of Margaret Thatcher.

Nigel Farage is the direct political descendant of the Grantham grocer's daughter. She hated the London intelligentsia as well, and the media. She felt the pain of people in Middle England who feel their culture was being "swamped", as she put it, by immigration. The people who can't afford houses that cost more than £1 million and don't employ Filipino nannies. She wouldn't have had Romanians living next door either.

Cameron, Clegg and Miliband are all products of the metropolitan elite and they speak the liberal language of gender balance, gay marriage and multiculturalism that Kippers loathe. There's a danger that the apparent resistance of London to Ukip, and the enthusiastic spinning of a few key results there, will mislead the Westminster parties into thinking they can ignore Farage, even though Ukip looks on course to win a historic victory in the European elections, the results of which are due tonight. Well, what does Europe matter so long as Hammersmith is painted red? Ukip won't be getting many seats at the next general election.

This would be a great mistake. Ukip is turning into a very British version of the grass-roots Tea Party phenomenon that has had a huge - if largely extra-parliamentary - influence on American politics. It nearly captured the Republican Party and forced congressional deadlock, which for a time made America almost ungovernable.

Ukip is now a political movement with depth, a lot of elected members and considerable fundraising ability. But most important of all it has the thing other parties lack: people. Nigel Farage is the only politician who can be guaranteed mass meetings across England (Scotland is very different, as we know, and now finds itself curiously in sync with the politics of suburban London). It is the nearest thing we have seen recently to a genuine mass political movement, and not merely a media front party serviced by PR agencies and electoral hired guns.

This is why Ukip seems to have an almost telepathic ability to communicate its message over the heads of the media. In the 1980s it was famously The Sun Wot Won It for the Thatcherite Tories, as it focussed the fears and aspirations of the lower middle classes. But The Sun tried to unwin it for Nigel Farage last week, calling him a racist, and Ukip hardly skipped a beat.

Indeed, in the final two weeks of the campaign, following his disastrous LBC interview, the UK media turned on the Ukip leader in a co-ordinated character assassination. But outside London it didn't do the trick. The decline of the press as a mediator of mass opinion is a sidebar to the Ukip story.

The Kippers may not translate their success into MPs at the next Westminster elections but, like the Tea Party, they doesn't really need to. Ukip just needs to set the terms of the debate on immigration and Europe - or rather, Britain's exit from it. David Cameron has insisted that the Tories "don't do deals and pacts" and that electoral co-operation with Ukip is not going to happen. But the quid pro quo is that to have any chance of victory in 2015, the PM is going to have to toughen his stance on Europe to attract Ukip votes - and allow members of his party to openly campaign for leaving the European Union in the 2017 referendum.

The Tories did badly last week, but not so badly as to rule them out of contention for 2015. Labour's lead was only about 3%, which, as Professor John Curtice has pointed out, is not nearly enough at this stage in the political cycle to give them a real chance at the next general election. Labour gained a lot of council seats, but Ed Miliband had a very uncomfortable campaign, with his failure to identify a local Labour leader, his ignorance of the price of his weekly shop and that bacon sandwich moment. These are such basic traps you wonder how any ­properly advised political leader could still fall into them.

He may have policies aplenty, but his brand-geek approach is becoming a problem and Labour know it. The backbench muttering has begun, and front benchers, especially the women, are complaining of being sidelined.

Meanwhile, Nick Clegg has presided over the virtual collapse of his party through being part of the Coalition. This is the worst crisis for the Liberals since Lloyd George's equally disastrous alliance with the Tories after the First World War. Clegg will have to go. There is no other way for the Liberal Democrats to restore their self-respect and their electoral appeal.

Clegg said they were victims of the "anti-politics" tide of public opinion, but the point is that the Liberal Democrats depend on anti-politics votes. Becoming part of the establishment has been a disaster. As Lynne Featherstone, the LibDem international development minister, said, the party has lost its "humanity".

The Scottish National Party used to depend on anti-politics votes too, though they have now almost become an establishment party in Scotland. However, the SNP's European election campaign was dismal and seemed to involve little more than party big shots taking flirty selfies with new candidate Tasmina Ahmed-Sheikh. I can't remember anything memorable that was said by the SNP apart from "we aren't Ukip".

By contrast, the Green Party put up a hell of a fight, using social media to great advantage - and were the only people who tried to make a constructive case for a reformed Europe. YouGov said they made the biggest advance of any party during the last two weeks. But the Greens do not get the kind of media coverage that for some reason the BBC accords to Nigel Farage and Ukip, and it remains on the margins. And the irony is that right-wing Ukip might benefit from the Green advance. If the SNP and the Greens cancel each other out, they may allow Ukip to come through the middle and win an MEP even though the Ukip vote is tiny.

However, the bigger question is how this will play in the independence referendum in September. As the UK Treasury made clear last week, Scotland desperately needs more immigrants, not fewer. Ukip is the BNP with a human face and its success is the final confirmation of the gulf in political culture between England and Scotland. The SNP will say - with some justification - that the only way to guarantee that Scotland stays in Europe and remains a socially liberal country is to vote Yes in September.