Oh, for the luck of the Irish. They are the only people in Europe to have a vote on the future of the European Union. That is thanks to their Constitution, not their leaders. Until recently the Irish Establishment had assumed that its citizens would rubber-stamp the Lisbon treaty, the repackaged EU constitution. Now, in the face of a formidable “no” campaign, it is trying to scare them into doing so. That tomorrow's poll is too close to call, in a country that has benefited so much from EU largesse, is a measure of how wrong-headed the whole process has been.

The Irish “no” coalition is a ragbag that includes Sinn Fein, pro-life campaigners and business executives. Like the French and Dutch rejections of the EU constitution in 2003, an Irish “no” vote would have its own parochial dimension. But that would not undermine its legitimacy. Most of those planning to vote “no” tomorrow have one thing in common: they do not trust a treaty that they do not understand. They show a good deal more common sense than the politicians.

The lack of clarity should make it impossible for any country to sign this document. It is a piece of deliberate obfuscation by technocrats who wish to proceed with a considerable erosion of national sovereignty under a smokescreen of “tidying up”. As a result of its vague wording, the treaty is dangerously ambiguous. Countries which imagine that they have negotiated opt-outs from unpopular bits risk finding out in years to come that the European Court of Justice takes a different view.

The “yes” camp argues that the Lisbon treaty is essential to the smooth functioning of the EU after enlargement, and that a rejection will throw the institutions into “chaos”. But the European Union is not paralysed. In the past year alone, 177 EU directives have passed into British law.

It is equally disingenuous to portray the treaty as a purely administrative exercise to cope with enlargement. A change in voting weights is an inevitable consequences of the arrival of new members, although small states such as Ireland stand to lose out disproportionately from that, and from the reduction in commissioners. But enlargement is no justification for the proposed removal of more than 40 vetoes in areas ranging from “economic co-ordination” to energy policy. The Lisbon treaty would give the European Court of Justice jurisdiction over crime and justice matters for the first time. It would make the EU a legal personality, able to sign treaties in its own right. Through a self-amending clause it would allow ministers to abolish national vetoes without any further treaty, and so without ratification by national parliaments or referendums. It is anti-democratic at its very core.

These changes, and others, would dramatically alter the powers of member states. Politicians hold these powers in trust for the people. They are not theirs to give away by executive order. Gordon Brown was wrong to insist that Labour's manifesto commitment to hold a referendum on the EU constitution did not apply to the Lisbon treaty. He has wilfully ignored the evidence of two select committees that the two documents were substantially similar.

The Lisbon treaty does nothing about EU corruption and waste, which have returned to centre stage this week. It does nothing about the EU's notorious farm subsidies. It enshrines, rather than bridges, the gulf between the public and the elite. Brian Cowen, the Irish Prime Minister, has implied that an Irish “no” vote would be a vote to “disengage” from Europe. That is disingenuous. An Irish “no” would signal that the elites must go back to the drawing board. Deprived of our own vote, we must pin our hopes on Ireland to speak for all of us.