The recent furore over MPs expenses means many people will either abstain from voting in the European elections, or else will cast a protest vote against the mainstream parties.
The British National Party stands to benefit greatly. Unlike a general election, there is a system of proportional representation in place. A share of the vote of 8 percent could see the BNP get a seat. If they get seats, they get hundreds of thousands of pounds of public money.
Last time turnout was 38 percent, and the BNP scored between 6 and 8 percent in the four main constituencies they're targeting. So it's easy to see how they could break through 8 percent this time, but would probably fail to if everyone voted.
Under the voting system - explained in this short animation - it's important to vote for a party that will score higher than the BNP. That's going to be Labour, Conservative, LibDem, UKIP and Green.
Especially crucial is the playoff for the final seat awarded in each constituency, likely to be between the parties coming fifth and sixth; ie likely to be between Green and BNP. An extra 3 percent on the Labour vote will probably make no difference, whereas that 3 percent going to the Greens would probably be the difference between a seat going Green or BNP.
If it sounds fiddly, or like the Greens are trying to scam for votes, check it out yourself. Here's last time's results. Here's an online calculator that can translate any breakdown you type in into seats.
In the North West, BNP leader Nick Griffin is standing. Griffin has made an excellent job of changing public perception of the BNP. Like the party itself, he has his roots in the National Front. The party prohibits non-whites from membership.
'All black people will be repatriated, even if they were born here,' Griffin told Wales on Sunday in 1996.
In 1997 he produced a publication called Who Are The Mindbenders, alleging that the media is run by Jews. He proved the BBC was Jewish controlled by naming 17 Jewish employees from a total of over 23,000.
During his 1998 trial that saw him convicted of inciting racial hatred, he compared the belief that six million Jews died in the Holocaust to the belief that the earth is flat.
The BNP are not just a little bit right of UKIP. They are a party of extreme white supremacism and racism. Many of their officials, including Nick Griffin, have convictions for racially motivated crimes. A seat in the European Parliament will massively boost their funds and their platform.
A vote for a party likely to score more than the BNP is a vote against the BNP. Please - especially if you live in their target areas of North West, East Midlands, West Midlands or Yorkshire and the Humber - make sure everyone you know who's registered votes against them.
Nick Griffin's march needs to end here.