The narrative says one thing but the numbers say another. Contrary to common wisdom, the UK Independence party — and its leader — seem to be holding up fairly well under fire.

There are plenty of accounts of the campaign so far that give the impression that things are not going so well for Nigel Farage and his party. He is supposedly flagging and frustrated, and far from confident that he can bag himself a seat in parliament.

Ukip is apparently being squeezed, getting less airtime than it had hoped for, while many voters who had toyed with the idea of voting for it are having second thoughts now things are getting serious.

This would be nice, especially for the Conservatives. Sadly for them, however, it is far from being the whole story. Mr Farage, as the leader of one of the UK’s no-longer-so-minor “minor parties” may not be Nicola Sturgeon, but he is certainly no Natalie Bennett.

The polls do not show Ukip’s early showing holding up as well as the SNP’s, but nor does the party seem to be fading like the Greens (although, even in their case, Labour and the Lib Dems still cannot sleep entirely easily).

Certainly, Mr Farage retains a degree of pulling power that the leaders of the three main parties would be happy to match — at least when it comes to television audiences. Some 2.5m tuned in to watch his one-on-one with the BBC’s Evan Davis: that was more watched than the equivalent interviews with David Cameron, Ed Miliband or Nick Clegg.

Whether Ukip’s leader has necessarily made the best use of his TV appearances during the campaign is more of a moot point. Few spin-doctors would advise their candidate to attack the studio audience as Mr Farage did during the so-called challenger’s debate.

Nonetheless, he decided to take on not only Mr Miliband, Ms Sturgeon, Ms Bennett and Plaid Cymru’s Leanne Wood, but also the select (and apparently carefully selected) few sitting in the stalls, accusing them of a “total lack of comprehension” and labelling them “a remarkable audience even by the leftwing standards of the BBC”.

Yet, like his remarks during the seven-way debate on so-called “health tourists” travelling to the UK to get free treatment for HIV, this was a perfect illustration of the fact that Mr Farage is playing a different game to his mainstream rivals.

Obviously, they, too, have to mobilise their core vote, inasmuch as any party has such a thing any more. But whereas they still have to spend much of their time playing centripetal politics — appealing, albeit from different points on the political spectrum, to the hallowed centre ground — Farage is a centrifugal force.

Ukip’s task is not to convert — that was what it was up to between 2010 and 2014, when it won 27 per cent of the vote at the European Parliament elections — but to preach to the converted. It is vital that they do not just stay at home and shout at the TV but get up off the sofa and go to the polling station on May 7.

One way to do that is simultaneously to tap into their well-established grievances, especially on immigration, and to their conviction that the media is biased against Ukip — something that, according to polls, eight out of 10 of those intending to vote for the party believe.

This aggressive doubling-down on Mr Farage’s part may be alienating the two-thirds of voters who, polls say, would not even consider voting for his party. And it may be eroding his personal ratings (although it is worth noting that, unlike Mr Cameron’s, Mr Clegg’s and Mr Miliband’s they are still in positive territory).

But for the moment anyway it looks like doing the trick — a win for Mr Farage in Thanet South, some second-places in Labour-heartland seats that might be won in 2020 and a vote-share in double figures.

Precisely how many Labour-Tory marginals Ukip winning over 10 per cent of the vote could cost the Conservatives is the subject of keen psephological argument. The answer, broadly and bluntly speaking, is almost certainly enough — not just in the sense of denying Mr Cameron a majority, but also threatening his grip on power. Things really are getting serious.

[Originally published at http://www.ft.com/cms/s/0/05c71f18-ea7b-11e4-a701-00144feab7de.html%5D