Blair has already snubbed the Electoral Commission over postal voting, and would have no scruples over rigging the battlefield where he thought he could win. However given current antipathy to the Euro and the EU, the chances are that he won't willingly give us a referendum unless practically all the other 'referendum' countries have ratified the Constitution.

(NB He didn't explicitly offer a referendum as reported on 20.4.04, although a conditional referendum was conceded in an interview on 15.6.04. (Source: No 10 website, www.pm.gov.uk/output/Page5962.asp).

Eurofacts noted that referendums are easier to win on the side of the status quo. What if the other 24 EU members (eventually) ratified the Constitution and gave Britain the ultimatum of signing up, otherwise they would break the current Treaty of Nice with us and replace it with their own Constitutional Treaty? And just to concentrate the mind, membership of the single market/European Economic Area would be available to us at even less attractive terms than Norway's to atone for the loss of our contribution?

It is unpredictable which way big business and the media would jump. Few would really want the Constitution and the Euro, but such have been the scare tactics - of Conservative collaborators as well as Britain In Europe - over the years that they might believe that there is no alternative to staying in the EU. (The BBC's Andrew Marr, who has been admirably objective, has also pointed out that to win, Blair would have to scare voters over withdrawal).

Blair would also wrong-foot the Conservative Party leadership by engineering an almost irreparable split. A majority of grass roots activists and voters are reckoned to want out. The anger that they would direct at their EU-committed leadership if they preferred to tolerate the EU would combust the Party. Even if Blair were to lose the poll, he would have torched the Opposition, and might risk either a cosmetically-enhanced re-run or a General Election that would confirm our EU future.

Even if Blair prefers a campaign that relies on spin, without any real threat of Britain being ejected from the EU, how keen would the Conservative luminaries be to stop the Constitution?

We must also ask how reliable is a Party leadership that tolerates MPs that support the Euro and the Treaty of Nice; a leadership that even cosies up to the ultra-federalist European People's Party, while slapping down patriots like Lord Pearson?

There may be well be individual clauses in the Constitution that the Tory Party would prefer not to have. But if the Government manages to provide the right reassurance on the most sensitive matters like oil and tax, how closely would the Tories fight over the incremental changes?

Blair could come up with plenty of examples of why the Tories were happy to have our laws decided in Europe - unless, of course, if the agenda was secretly withdrawal. (Which Howard would vehemently deny). Blair's follow-up questions would taunt that they were happy to have other policies agreed at EU level as it gave Britain 'influence in Europe'.

In 2001, Blair embarrassed Hague by asking if the single currency was so bad, why did he only commit to stay out for five years? Blair would taunt Howard that if the Constitution was so bad, why would he not consider withdrawal if it was ratified?

Apart from causing embarrassment as there would be no convincing reply, this inability to admit past mistakes would also serve to expose divisions in the anti-Constitution camp.

This would be a boon to New Labour, whose spin-doctors, short of any real arguments for the Constitution, would seek to highlight personalities and image rather than substance. They would seek to wing the vote on a combination of creating fear and damaging the credibility of the 'No' campaign in the hope that its supporters will be put off voting.

This would happen irrespective of UKIP - first, as government dogsbodies like Robin Cook are happy to put words into the Conservative Party's mouth, and second, as there are several documented cases of individual Conservative politicians supporting withdrawal.

Replacing EU membership with free trade and co-operation as a sovereign nation is at least a consistent alternative. The Tory position of being 85% 'ruled by Europe' rather than 95% is full of contradictions and sustainable only as the immediate status quo.

The anti-EU camp could win the day while portraying withdrawal as the only long-term way to safeguard our national sovereignty, our legal system, our currency, our tax advantages and our jobs. A status quo of sorts.

But, for reasons covered, it will have to:

• show how current membership threatens us,
• show how 'EU reform' is not an option and
• cement confidence in a post-EU future.

(This is no mean task, but any campaign requires hard graft, and there may be a year or two to do it. Patriots believe that it is necessary anyway, as a referendum is not guaranteed).

So long as an 'agree to disagree amicably' approach is managed, a diverse coalition can win a straight vote on the Constitution.

• The Danish 'No' campaign in 2000 was a very loose coalition of political opponents, but at least they did not attack each other, but concentrated on the issue of opposing the Euro.
• The Australian 'republic' referendum was won partly because the monarchist vote was supplemented by the votes of a substantial number of spiritual republicans. The latter were unhappy with either the detail of the proposals or their government's arrogant approach.