Green Party leader Natalie Bennett went to the Romanian Cultural Institute yesterday to call for an end to immigrant bashing (you can read the full speech here). This wasn’t just the right thing to do. It was also cunning politics.

It is, of course, a risk. Most of the people in the country support ever stricter immigration controls. There is a case that Greens are better spending our time talking about the problems for which people believe immigration is responsible – the housing crisis, unemployment the loss of community – than on talking about immigration itself.

I have sometimes made this case. But I think that it no longer applies. In particular, two things have changed.

The first thing is what we might call the facts on the ground. Actual immigration law has become significantly more brutal over the last few months. Huge numbers of people will be hit by cruel and perverse laws. Natalie gave one example in her speech: “18,000 British people will be prevented from being reunited with their spouse or partner in the UK annually as a result of the new rules”.

A recent report from the British Council hammered the government, saying its new visa laws are a huge threat to British universities. And, my experience, students know it – standing up for international students is now a mainstay of student election manifestoes across the country.

And then, of course, there are immigrants themselves – more than 10% of the British population are being scapegoated for all of the country’s problems. Whether or not visa laws have hit them or their loved ones, they feel the heat. Most of them have votes – in local and Euro elections if they’re from the EU, and in all elections if they’re from a Commonwealth country (and most immigrants here are one or the other).

Recent immigrants to the country don’t suffer from the affliction of a long standing family history of voting for one British party or another. They often cluster for safety in geographical communities, meaning they are relatively easy to organise in first past the post elections.

The second thing which has changed is the politics. With the rise of UKIP, Labour and the Lib Dems have both tacked significantly to the right on immigration in the last few months. For the 60% of young people, for example, who say that they would not be attracted to a party which pledged to stop immigration, the lack of anyone representing them is a real frustration.

More broadly, the rise in UKIP has changed the rhetorical playing field in important ways that we have to get our heads around. Because for all that they might be seen as a single issue party, the truth (as Peter McColl has argued) is that they are a culture war party: they are our tea party.

And, like every kind of war, culture war is polarising. People know which side they are on, and if you try to straddle a divide, you will be punished for it. If you bravely represent your side, they will treat you like a hero.

And in our culture war, immigration has taken on a whole different meaning. It is becoming to British politics what abortion is to American politics – a key identifier, the flag you wave to signify which side you are on.

This poses a huge opportunity for Greens. Because in a multi-party democracy, being the only people speaking for a minority when everyone else speaks for the majority gives you a good chance at representing a plurality. At the very least, there are many votes going begging.

For the first half of this year, I was managing a Green county council election campaign in Oxford. We had, initially, decided that our core messages would be about cuts to care services, and a local planning issue. But as the election progressed, we became aware of a problem with this. Whilst Labour nationally say they will keep all of the cuts, locally, they say they oppose them. And Labour were – as they are in many Green target seats – the key competition.

It is very hard for Greens to beat the much better known Labour party by saying the same thing as them. And so, in addition to those two messages, we trialled a third – ‘stand up to the immigrant bashers’.

It went down brilliantly – one of the rare times I’ve had voters actively say ‘I LOVE that – that’s why I’m voting for you’. It was certainly a key factor in us winning the ward with a thumping majority, as voters rewarded us for being brave, being different, and standing out on an issue where they had seen every other party sell out.

Now, not every seat in the country is as international, or as full of students, as central Oxford. I certainly wouldn’t say all Green campaigns should put the issue on the front page of their flyers, as we did. And I am certainly not arguing that we should stop talking about cuts, or about housing.

But what I am saying is this: a significant minority of people across the country have watched on in horror in recent months as first UKIP have taken off, then the other parties have followed them into the nasty sport of xenophobic scapegoating. They are looking for a party to stand up and proudly represent them: to get in the middle of the fight and to take on UKIP directly. Greens can be that party. Or we can stand on the sidelines.

Being controversial is scary. But the opposite is being ignored.