Parliament has broken up for the summer. But it has broken down for good. Back in April — before the expenses scandal fully broke — the Labour MP Frank Field wrote on his blog: "Week after week, MPs have been turning up but with almost no serious work to do...The whole exercise is vacuous." That period now looks like something of a golden age. In the weeks since then, the public's pickpockets at Westminster have been turning up with nothing to do other than check whether their office neighbours have jumped out of the window.

What we have seen from the expenses row, through the aborted coup against the Prime Minister and finally to the European elections, is that the main political parties in Britain have become useless as reflectors or the concerns of the public they presume to represent. After a pitiful showing in the European Parliament elections, and a pitiful reaction to that pitiful showing, it has become clear not simply that the main parties are incapable of rising to the challenges they face, but that they are actively creating and causing many of those challenges.

The failure of Westminster in its current guise is nowhere better demonstrated than in the major parties' refusal to recognise messages even when given in a resounding, often shockingly clear voice. The UK Independence Party (Ukip) coming second in share of the vote still doesn't seem to be enough to make the parties wonder what they were being told about Europe. And even the election of two British National Party MEPs has not provided the much-needed wake-up call.

Gordon Brown and David Cameron practically compete to misunderstand the significance of that event. At Prime Minister's Questions, Cameron tried to seize fairly easy moral high ground by dropping in, correctly, the fact that the BNP were thugs and fascists. Brown responded: "On the Labour side of the House, we will do everything in our power to show that the problems that made people vote for the BNP are the problems that we are dealing with — on housing, on social justice and on employment."

Which is to miss the point rather spectacularly. But the PM is not the only one. At a recent meeting in Westminster, I questioned one of Cameron's key strategists about what the party was planning to do to stop the BNP's rise. I was told that internal polling showed that while disenfranchised Conservative voters go to Ukip, it is disenfranchised Labour voters who go to the BNP. In other words, he spelt out smugly, the BNP was not a problem the Conservatives could do anything about.