If people were saying things about you on television and in the newspapers, would you let them get away with it without having a say yourself? Well, thousands of immigrants do just that. Despite being at the centre of this election campaign and often having the right to vote here, very few turn out on polling day, with many oblivious to the debate going on around them.

In fact, a recent poll found that only 16% of Polish immigrants have voted in a European election in Britain (as opposed to in their home country), with fewer than half being aware of UKIP. I want to know what it's like to be at the heart of the debate without even realising it, so I set off to Lincolnshire to meet Konrad Lucki.

Konrad came here ten years ago from Poland to work as a taxi driver. He's heard a fair few views in his cab, but with polling day fast approaching, we drive to Brigg to gauge the latest feeling on immigration.

We do meet some who say immigration is good for the country, but a group of men in their 20s sum up the majority of views: "Two or three of our best mates are struggling like hell for work and then there are Polish people coming into the country. They're in here for three months and then they can claim on the dole - claim what we're effectively paying in tax."

I ask Konrad whether that's difficult to hear. "Yes it is hard", he says. "A lot of the jobs we do, the English people don't want to do. For example, my first taxi company boss employed me because none of his English friends wanted to do that job."

Given his frustration, I also ask Konrad whether he'll vote. He's keen, but we soon discover he's too late to register. That's one of the major stumbling blocks for immigrants - very few are registered, often because they don't even realise an election is taking place.

Back in London, I meet Dorota Zimnoch from the Polish City Club, who's focusing her efforts on that very issue. She thinks she's got about two thirds of Poles registered this time, using a mixture of campaign videos and leaflets.

With surveys suggesting that Poles favour the Liberal Democrats and are least likely to vote UKIP (contrary to the wider population), Dorota is keen to stress she's not promoting any particular party. But she says, "We want to give Polish people the opportunity to hear what the parties are saying. We hope that if they hear that they are not welcome here and they feel emotional about that then they will use their vote to object to that, though there may be other more important factors for them."

And what about those individuals who have been pushing immigration up the agenda in recent years, do they feel comfortable that they are conducting a debate that excludes - intentionally or not - the very people at the centre of the discussion? "The fact is that they have the right to vote", says Alp Mehmet of Migration Watch. "If you're asking me whether we should be using resources to encourage other EU nationals to get out and vote? No, I most certainly do not think we should be doing that."

His point is that there are already general campaigns to encourage people from all walks of life to vote. And research suggests that more Eastern Europeans - particularly Poles - are at least registered to vote this time around. But the curious fact remains that while immigration is at the very centre of this election, thousands of immigrants will find themselves left outside the debate altogether.