Some candidates say they wouldn't attend European parliament if elected
For some smaller parties standing in the European elections in Wales the row over MPs expenses is a chance to get across their sceptical message on the EU.
These are parties who believe they might have most to gain from any voter disillusionment with the political system.
They talk of outrage and anger of the electorate but know too it could work to their advantage if the feeling is translated into disenchantment with the major parties.
UK Independence Party (UKIP) gained a dozen seats in the European elections of 2004, though none in Wales, but are now down to nine.
They are standing on a platform of withdrawal from the EU and "free trade and friendship" with European neighbours not political union.
And for the party the current controversy over MPs expenses shows how many politicians simply do not understand what voters really think.
"They have shown themselves to be totally out of touch with the rest of us," said John Bufton, UKIP's lead candidate in Wales.
"The flipping of homes and creative accounting that has taken place needs to be fully investigated."
The revelations form part of a wider problem with politics for John Bufton with a system full of too many professional politicians.
"In Wales we have too many paid politicians... do we really need all these career politicians on huge salaries and expenses?"
The party's candidates standing with John Bufton are David Bevan at number two, number three Kevin Mahoney and David Rowlands, number four.
At the other end of the political spectrum, the left-wing No2EU Yes to Democracy group also oppose the idea of what they see as "professional politicians".
Robert Griffiths, their lead candidate in Wales, said he wouldn't even attend the "sham" parliaments in Brussels and Strasbourg if elected.
"We share public outrage," he said.
"It is a symptom of the professionalisation of politics."
Apart from Robert Griffiths, the other candidates are Robert Williams at number two, and Laura Picand and Trevor Jones at numbers three and four.
Abolishing capitalism and replacing it with a socialist system is the overriding aim for the Socialist Labour Party - and like the other groups the expenses controversy shows the corrosive effect of having "career politicians".
"The recent expenses scandal cannot fail to appal and disgust all who have followed, even in passing, the nauseating details," Ian Johnson, the Socialist Labour Party general secretary, has written.
The European elections offer a platform for another of their key aims - to pull out of the EU altogether.
In Wales, the lead candidate is Robert English, second Richard Booth, with Liz Screen at number three and Judith Sambrook number four.
The British National Party says it wants a police investigation but their lead candidate Ennys Hughes talks of a "free-born Briton" being innocent until proven guilty.
The other candidates are: Laurence Reid, Clive Bennett and Kevin Edwards.
Different parties with different aims - but all want to benefit from the crisis engulfing British politics with the expenses controversy. And that's the real fear of the major parties in these European elections.