OUT canvassing with Darren Hall, a candidate for the Green Party in the constituency of Bristol West, you would never guess British politicians are generally hated. On a pavement in Stokes Croft, a grungy area of Bristol thick with students, the former Royal Air Force engineer stands shivering on a wintry evening, hugging copies of “Bristol Green News”. Seeing his green rosette, many passers-by stop to ask about inequality and pollution and, more often than not, declare their support for him at the general election due in May. Why? Bagehot asks one, a lank-haired man called Roy Cole. “Because I’m a conscious individual!” he exclaims—adding that “most people call me Roy the Raver.”

When David Cameron, the Conservative prime minister, famously accused the UK Independence Party (UKIP) of being stacked with fruitcakes he perhaps had the wrong party in mind. A radical left-wing outfit, dedicated to reducing inequality by doling out a stipend to every adult Briton, the Greens are far dottier than UKIP. They are surging nonetheless. Having doubled their membership—to around 30,000—over the past year, they are now scoring about 8% in the opinion polls. That is around the same as the Liberal Democrats, Britain’s erstwhile left-wing protest party and Mr Cameron’s coalition partner, whom the Greens bested in the last European Parliament elections. No wonder the verdant insurgents demand to be represented, alongside UKIP, in the televised debates expected before the election; they have earned it.

They appear likely to retain their single parliamentary seat, Brighton Pavilion, in May. With a bit of luck, they could also win their two target seats, Bristol West and Norwich South. Bristol, where the Greens’ growth is explosive, has a history of non-conformism—from Methodism in the 18th century to the graffiti artist Banksy and the Bristol Pound, Britain’s first city-based currency, today. The People’s Republic of Stokes Croft, as the squatters who have taken over Mr Hall’s campaign turf call their area, is especially Green-friendly: a place of freegan food banks, café-squats and riots against supermarkets, it could provide the party with the eager activists it will need for the fight.

The Greens have been here before. In the 1989 European Parliament elections they came from nowhere to get 15% of the vote, the implosion of the SDP-Liberal alliance having unlocked a raft of left-wing protest votes. Much the same is happening now, with a lot of the party’s new fans coming from the Lib Dems, who have lost around three-quarters of their vote since palling up with the Conservatives. This time, however, the Greens have a good chance of hanging onto their new supporters.

They are unlikely to return to the Lib Dems, the experience of government having exposed a gulf between the party’s pragmatic leadership and its rowdy left-wing foot-soldiers. The catastrophe that has befallen Britain’s former third party is also part of a broader electoral fragmentation, which has made voting for fringe outfits less pointless. Neither of the two big parties, the Tories and the Labour Party, looks able to win a majority in May, which raises a prospect of coalition or minority government in which a mere seat or two could prove influential. And there is no reason to expect two-party, majoritarian politics to return soon. That, in turn, could argue for electoral reform, perhaps including the introduction of proportional representation, muses Natalie Bennett, the Greens’ leader, which would help small parties even more.

A likeable Australian, Ms Bennett is another element in the Greens’ success. A few years ago, the party disdained to have anything so oligarchic as a leader. It had a “principal speaker”, a role that was scrapped, joshes Ms Bennett, because no one was sure how to spell it. With a London office, 15 professional staff and a recruitment drive in the offing, the party is now more professional.

Bagehot, who worries a lot about the environment, wishes he could feel more enthusiastic about this. But the Greens’ grasp of economics is about as secure as an empty Stokes Croft office block. “Basically what we need to do is to completely restructure society” away from “hyper-capitalism and neoliberalism”, says Ms Bennett. Without wishing to second-guess the local branches of her party who will collectively draft the party’s manifesto, it seems this restructuring would involve a massive expansion of the welfare state (because “people cannot live on the benefits we have now,” says Ms Bennett), a massive increase in subsidies for renewable energy and throttling taxes.

It’s a sandal! It’s an outage!

That would nobble the British economy. It is not obvious what it would do to reduce climate change —which, in fact, the Greens appear to have given remarkably little thought to. They talk about the world sparingly and mainly to illuminate leftist British issues. They are broadly against consumption, for example: “The world is sodden with stuff, it cannot have more stuff,” said Ms Bennett. Yet they do not appear to have considered what that would mean for billions of the world’s poorest people, almost none of whom live in Britain. When Bagehot suggested to her that there was a problem with this, Ms Bennett said he was worrying too much: to be poor in India wasn’t so bad as to be on benefits in Britain, she suggested, “because at least everyone else there is poor too”.

That is contemptibly naive and also a shame. The world could use an economically literate and intellectually courageous British environmental party. The way Westminster is going, such a party could also end up with real power. But Ms Bennett’s outfit is parochial and recidivist, a big fish in a muddy left-wing puddle, and that is not much use to anyone, despite some of its members’ touching goodwill.

“Exchange is not robbery!” said Mr Hall amiably, swapping a Bristol pound for the real thing with Bagehot. Eureka! your columnist thought.