It is the classic vicious spiral.

The European Parliament lacks legitimacy, so voters are alienated and do not vote for it. Low turnouts further damage the Parliament's legitimacy. Thursday's Euro elections do not seem likely to reverse the trend. Across the EU, turn-out is forecast to fall below the 43% recorded in 2009. It has been widely predicted that more than one-quarter of the candidates elected this year will be eurosceptics of some kind.

Elements of the EU institutions remain deeply undemocratic. Despite tweaks, nobody votes for the commission and the powers of the Parliament are in many ways limited. The scare stories about losing powers to Europe do not chime with people's actual experiences that the governments that make the biggest difference to their lives, through the decisions they make, are still the Westminster and Holyrood ones. Despite the rhetoric, for the most part Europe cannot do very much without the approval of national governments.

However, the vast majority of what the EU does requires the Parliament's assent and more and more decisions are made at EU level. It does matter. So why are voters so alienated? One reason is the remoteness of the Parliament. Few of us know who our MEPs are or see enough of them to understand what they do. We elect from party lists and those chosen join large transnational voting blocs.

The Parliament is hugely expensive, partly as a result of having to work in two dozen languages, but, at £1.42 billion (€1.75bn) a year, it is more expensive than the British, French and German parliaments combined. Some of this is unnecessary and wasteful. There is no purpose to the Parliament's Strasbourg base and working between there, Brussels and Luxembourg adds £147 million to the cost.

Criticism of the EU is growing even in the heartlands of the European project such as Germany and the Netherlands. Yet some of the more sceptical countries, particularly the Scandinavian ones, may offer a way forward. There, national governments take a bigger role in scrutinising EU legislation. This has the twin benefits of holding the Parliament to account and bringing its workings to voters' attention. This election campaign has been eclipsed in Scotland by the independence referendum, in which many people feel much more engaged. It will have significance for that campaign, too. If the SNP were to win Scotland's sixth Euro seat, potentially the party's third, that would hand the Yes campaign a psychological boost. It would also shut out Ukip, validating Alex Salmond's strategy of painting the party as signifying a fundamental difference between politics south and north of the Border.

Ukip leader Nigel Farage has given voice to opinions many people find distasteful. But the fact so many voters feel ambivalent about the EU only helps amplify the views of those who despise it. Failing to turn out to vote amplifies their voice within the Parliament. Voters should have their say, and make an effort to understand what they are voting for. A more democratic Europe depends on breaking the pattern of illegitimacy.