The exit beckons for Britain

As EU leaders gathered for their latest summit, Britain's Euro sceptics fired their heavy artillery rounds. The Conservatives, the Sun, Mail and Telegraph whipped themselves into a fury, convinced that if they took their analysis of the EU reform treaty to new hyperbolic heights, they could force the government to offer a referendum. After all, they forced Tony Blair into such a retreat on the earlier constitutional treaty, in 2004, after he had said he would never do such a thing.

Britain's beleaguered pro-Europeans are now invisible. Gordon Brown, with an eye to the gallery, has threatened to veto any deal that does not respect his "red lines" - although his negotiators have already secured all their objectives.

Amid all the theatrics, a potentially more dramatic issue is at stake. It is rarely mentioned. If Brown succumbs to the pressure and holds a referendum, and if, as would almost certainly be the case, voters say "No", while all the others backed it, Britain would find it virtually impossible to stay in the EU. Technically, a new treaty cannot be implemented unless every member-state ratifies it. In practice, however, the other 26 would not be prepared to forget about the reform treaty - the fruit of six years' work - and live happily with the current, inadequate arrangements.

In such a scenario, the British should not expect their partners to offer concessions in order to make the treaty more palatable. They are fed up with us. During the negotiations in the Constitutional Convention, and two subsequent intergovernmental conferences, the UK has insisted on "red lines" and opt-outs, got what it asked for, and has come back and asked for even more. It has won all the substantive arguments by threatening to use its veto. As a result, the reform treaty has the Union Jack painted all over it.

If the British said "No", the country would be given time to reconsider. If it did not change its mind, it would be offered a status similar to Switzerland's or Norway's - in the single market, but outside the EU and unable to vote on its rules. The other member-states would renounce the existing treaties and readopt them - and the reform treaty - but without Britain.

So how likely is a British referendum? Might Brown follow Blair's example and cave in to the tabloid-led campaign? Ministers are adamant that this treaty will be ratified in parliament, and in parliament alone. They are likely to defeat Tory amendments in both houses that call for a plebiscite. In the Commons, a few dozen Labour rebels may vote with the Tories, but the Liberal Democrats' leadership, if not all their backbenchers, will side with the government.

But what if the Mail and the Sun decide to make Brown's life a misery unless he grants a referendum? Labour's weak position in the polls may make it harder for him to resist. The Conservatives are attacking him for "reneging" on the promise of a referendum, and thus being untrustworthy. Some of the Prime Minister's aides could thus see the offer of a referendum as a means of restoring trust in him and keeping the tabloids onside.

Face down the foes

It is not hard to mount the argument against a referendum: the reform treaty's most significant innovations - such as reducing the role of the rotating presidency, and merging the jobs now performed by the high representative (Javier Solana) and the commissioner for external relations (Benita Ferrero-Waldner) - reshuffle existing institutional arrangements. Compared to earlier EU treaties, such as the Single European Act and the Maastricht treaty, the reform treaty does not shift significant powers from the member-states to the EU.

But the government cannot easily make that case, because it did, foolishly, promise a referendum last time around. The old constitutional treaty's provisions are similar to those of the reform treaty, as the Commons EU scrutiny committee has pointed out. Yet ministers are right to argue that the form of the new document - an amending treaty - is different from its predecessor, which consolidated all previous treaties into one text, with constitutional trappings. They are also correct in saying that the special provisions applying to the UK, including de facto opt-outs from important provisions on justice and home affairs, social policy and the Charter of Fundamental Rights, mean that, as far as it applies to Britain, the reform treaty is quite different.

I predict that the government will face down the tabloids. It knows that Europe is not an important issue for most voters. Those who really do care are going to vote Tory anyway. If Brown did grant a referendum, he would look weak. And the government would almost certainly lose it, further energising the Conservatives in the run-up to the election.

If Brown and his ministers want to prevent the referendum campaign gathering momentum, they will need to go on the offensive, arguing the case for the reform treaty, rather than looking sheepish and defensive, as they do now.