Tomorrow the election that never happened will take place. The almost complete absence of any serious debate about European issues is a colossal indictment of the European Union (EU). The initial purpose of the EU - to bind together nations that had recently been at war - was exhausted by success. As soon as politics replaced conflict, the EU began to limp through institutional wrangles, mostly invented for the sake of having something to do. It created an empire but failed to find a role.

A serious debate about Europe would address this existential question. But no such debate is on offer. Neither is there any genuine debate about the poor job that the European Parliament does in scrutinising the European executive. Instead, the election is being dominated by the saga of MPs' allowances, reshuffle rumours, the bidding war to promote constitutional reform and the increasingly desperate struggle of the Prime Minister to project an aura of authority.

To the extent that the election has any European content at all, the electorate is being asked to adjudicate on relatively footling matters such as with which group of parties the Conservative MEPs decide to sit. Perhaps the only party that has campaigned on Europe has been the United Kingdom Independence Party (UKIP), for whom it is the issue that surpasses all others.

This election ought to be a verdict on the way this country's relationship with Europe has been handled. Despite the inability of the political class to make a coherent case for the EU, it is still open to voters to make their assessment on that basis and it has to be said, that there is no obvious winner.

The Green Party makes a good case on its central issue but its commitment to disastrous protectionist economics makes it an inappropriate choice even if one were to declare a plague on all the other houses. The Liberal Democrats have softened the federalism that was once their distinctive mark. That is a welcome move but, although they make their case well, their position is well-meaning but ill-considered; they remain too uncritical of the effect of European legislation on British life. At the other end of the spectrum, UKIP has a clear position - to withdraw from the EU - which is not in the British national interest.

Of the two largest parties, Labour ruled itself out by the refusal to redeem its manifesto promise to hold a referendum on the European Constitution. It is specious to argue that the Lisbon Treaty is so different from the original Constitution that the promise is now redundant. The two documents are all but identical and the pretence that they are different is an unworthy attempt to smuggle in a treaty comprehensively rejected by the people of Europe. The saga of the Constitution is a parable of the detachment of the European elite from the people that needs to be corrected. The failure to grasp this basic point disqualifies Labour from serious consideration.

So, by a process of elimination, that leaves the Conservative Party. The future of a viable EU surely lies in concentrating on those issues, such as the response to climate change and the need to secure energy supplies, on which co-ordinated work between governments is vital. That means it needs to spend a lot less time on pointless internal deliberation designed to cement power centrally, of which the Lisbon Treaty is an example.

The Conservative Party has the only manifesto which contains both these defining ideas. On that basis it merits support in tomorrow's election. But the bigger issue is, in fact, whether an increased Conservative presence in Strasbourg can make any difference in finding a purpose for the European Parliament which, just at the moment, it palpably lacks.