Leading article: Britain must look beyond the opt-outs and red lines

Leaders of the 27 states that now make up the European Union gather in Lisbon today for a summit that will, if Britain allows it to, lay down the foundations for this enlarged Europe. On the table will be the Reform Treaty, the modestly-named successor to the Constitutional Treaty, which came to grief 18 months ago in referendums in the Netherlands and France.

This summit has long been seen as a crunch point for the Union, a test of both purpose and nerve. So we should start by hailing the achievement. For the EU to be considering the final draft of a shorter, less ambitious treaty so soon after the referendum debacles testifies to the determination of the Union to endure. The mood in Lisbon may be less than euphoric, but it is very far from the abject despair of late 2005.

Unfortunately, but all too predictably, the effect of those "No" votes was more damaging to the European cause in Britain than almost anywhere else. It gave new heart to those hostile to the EU and all its works, allowing them to claim – quite wrongly – that the voters of two founding EU states were on their side. But blame also rested with Tony Blair. It was his decision to grant the principle of a referendum in Britain – as a ploy to keep Europe out of the election campaign – that bounced President Chirac into holding one in France. That "Non" simultaneously freed Mr Blair from his referendum promise and the treaty.

The return of the treaty, in any form, was bound to rekindle those passions. The result was that Gordon Brown spent his first months in office fending off renewed calls for a referendum, while contemplating an election. In his manifesto commitment to a referendum, Mr Blair had bequeathed his successor a big liability. To avoid a referendum, Mr Brown had to demonstrate how different the new treaty was from the old. The Commons select committee's conclusion that the two were not so very far apart did him no favours at all.

The courageous choice would have been for Mr Brown to take the Euro-bull by the horns and fight an election on that issue. We continue to believe that, with an energetic campaign fought on the facts by politicians of conviction, neither a "Yes" vote in a referendum nor an election victory on the Europe issue would be impossible. Either would have been another way in which Mr Brown could have distinguished himself from Mr Blair.

That this is not the course he took is no excuse for the apologetic campaign ministers have waged in the run-up to Lisbon. All they have talked about is what we will not sign up to, what "red lines" have been drawn and what opt-outs negotiated. We have heard almost nothing about the benefits of EU membership or the merits of the Reform Treaty. Why have nominally pro-Europe Labour governments been so defensive towards their voters in anything to do with the EU?

The case for the Reform Treaty is unimpeachable. Structural change was necessitated by enlargement – a policy that Britain enthusiastically embraced. The treaty itself enshrines nothing that threatens this country's autonomy of action at home or abroad. Its chief effect should be to help the EU to function better, with more accountability. There is nothing wrong with that.

We see rather more hostages to fortune in those opt-outs and "red lines". Not only do they confirm Britain's common image as Europe's most grudging partner, they also stand to exclude us from much beneficial cooperation. International crime, terrorism, migration and climate change are all areas which positively demand a joint approach and joint action. The voluntary sharing of some sovereignty for mutual interest is one of the EU's most envied successes. It is of this, not "red lines", that ministers should be boasting.