The working text for the EU treaty was published in English for the first time at the end of July. We can now see more clearly than ever that this new treaty is essentially the old EU constitution, rejected by French and Dutch voters just two years ago, but brought back under another name.

Or rather it is clear only when the deep legal obscurity of the text has been penetrated. That obscurity is deliberate. As Giuliano Amato, the former Italian Prime Minister and vice-president of the body that drafted the original constitution said, the treaty’s draughtsmen “decided that the document should be unreadable. If it is unreadable, it is not constitutional, that was the sort of perception.”

However, just about every European leader has been happy to boast about how much of the old constitution has been revived: 90 per cent, according to the Irish Prime Minister, 98 per cent according to the Spanish Foreign Minister, who explained “the wrapping has been changed, but not the content”. Even Gordon Brown let slip after a meeting with a fellow European prime minister that they had “discussed the European constitution and how that can move forward”.

So there can be no pretence that the EU constitution has not been brought back. Naturally, more and more people are wondering what has happened to the referendum they were promised on it.

All MPs were elected on manifestos promising the British people the final say on the constitution in a referendum. Mr Brown has no mandate to sign up to 98 per cent of it and ram it through Parliament without so much as a by-your-leave from voters. David Cameron pressed Mr Brown on this point in the last Prime Minister’s Questions. In response Mr Brown produced three arguments why there was no need for a referendum.

First, he said that all the Government’s negotiating objectives had been achieved. But the Government did not object to the creation of a new EU president, the loss of at least 60 of our national vetoes, granting the EU the power to make treaties, the widening of the EU’s powers elsewhere or a new ratchet clause that would allow any veto outside defence to be abolished and the Brussels institutions to strengthen their role without the need for a new EU treaty.

Even if all the objectives the Government set itself have been met, the bulk of the constitution has still been brought back. But the negotiating objectives themselves were seriously inadequate and the Government’s claim to have achieved them falls apart on examination.

Its boast to have safeguarded our foreign policy turns out to be based on a clause in the treaty that would not even be legally binding. Its claim that it has stopped the Charter of Fundamental Rights from changing laws in the UK “in any way” is shot through with holes. The Swedish Prime Minister told his parliament that “it should be stressed that the UK was given a clarification, not an opt-out”.

The safeguard against the new powers over criminal justice that the treaty gives to the EU is weaker than it looks. EU judges will have the power to rule on existing and future EU agreements in an area that has been until now wholly intergovernmental. Indeed, the EU Justice Commissioner said that he will use these new powers to the full. Over time, we could see our criminal justice system changed against our wishes.

As for the last of these so-called red lines, on tax, a government spokesman privately confessed to one BBC reporter that “it was a bit of a con” and “purely presentational”.

The Government’s claim to have safeguarded our interests is about as credible as a student who set his own exam paper, marked it himself and then awarded himself an A-grade.

Mr Brown’s second argument against a referendum is to quote a line in the treaty agreement that says the “constitutional concept . . . is abandoned”. But the next line says that everything in the original constitution would be kept, unless stated otherwise – and according to a study by the think-tank Open Europe, only 10 out of 250 proposals in the constitution have been changed. As dozens of senior EU politicians have said, this is the same content with a different label. The original constitution’s chief author, Valéry Giscard d’Estaing, explained it succinctly: “Making cosmetic changes would make the text easier to swallow.”

Mr Brown’s last and weakest argument is to claim that none of this matters because it is an “old agenda”. But nothing can be more central to today’s politics than the restoration of trust, badly damaged by ten years of Labour government. As Gisela Stuart, the Labour MP, said: “It has everything to do with the new Labour agenda: there was a manifesto commitment to a referendum on the EU constitution”.

Just before becoming Prime Minister Mr Brown reminded his party that “the manifesto is what we put to the public. We’ve got to honour that manifesto. That is an issue of trust for me with the electorate.” Yet the Labour manifesto he was talking about promised a referendum on the constitution.

Mr Brown talks endlessly of a new era of openness and accountability. He says he will consult and listen more. Yet he now proposes as his first big decision as Prime Minister to break a solemn manifesto promise and deny the British people their say over who governs Britain and how it is governed. But how can he expect the British people to trust him if he does not trust them? How can he listen to people if he will not let them speak?

Mr Brown’s convoluted arguments against a referendum do not stack up. By contrast our case is simple: this is the EU constitution in all but name, the British people were promised a referendum on it, so let them have that vote.

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