The defence secretary, Michael Fallon, is under siege. He is being swamped with criticism. He has used the language of plague and war to describe how the residents of British towns feel about immigrants, even though this is broadly considered to be an unhelpful and cheap, populist way of discussing profound demographic change in the UK. Downing Street has been quick to disassociate itself from such intemperate language. Ukip, universally viewed as the political force that is persuading Conservatives to ramp up their anti-immigration hyperbole, has been quick to point out that their political opponents would be very annoyed if their own campaigners started using words like “swamped” and “siege”.

Yet, such language attracts votes. It must be annoying, seeing your power base slip away, simply because your bosses don’t want you articulating how you reckon your constituents feel. Fallon, no doubt, is annoyed. Why shouldn’t he be allowed to express thoughts that chime with those of potential voters? Well, first, such words are divisive. And, second, they are hypocritical.

Politicians have had decades to explain that high levels of immigration are part and parcel of neoliberalism, because they offer speedy, few-questions-asked economic growth. For some reason, however, both Labour and the Conservatives have shied away from explaining to “ordinary people” that immigrants provide a steady supply of labour, stopping “ordinary” wages and expectations from getting out of hand. It’s a strategy that has placed Britain in the extraordinary position whereby it now has a record number of people in low-paid jobs amid historically low levels of wage inflation. That’s a hard “achievement” for any political party to sell. So they simply don’t try. Labour and the Conservatives just carry on blaming each other, while at the same time quietly getting on with the real business of nicking each other’s policies.

Ukip, however, has been happy to step into the empty space the mainstream has created, merrily stirring up resentment by linking low wages and immigration, as if this is the personal fault of immigrants, rather than an inevitable aspect of globalisation. Of course, Ukip would come unstuck if they achieved power and revealed themselves as every bit as neoliberal as all the others. But that’s not something Ukip needs to worry about too much yet. Their power to set the agenda comes without responsibility. That’s what makes them so dangerous.