Next week’s crucial summit will determine the rules by which Europe runs. Britain, along with three or four others of the 27 members, has deep objections to parts of the treaty – mindful of the effects it could have on domestic politics for years to come. Angela Merkel’s six “discussion points” give Britain far more cause for worry than it had expected. But it is Poland which still threatens to bring the whole enterprise down.

That is not because Poland is particularly stubborn – although it is – but because it objects to the essence of the new rules on voting, and without that the treaty is nothing.

Whatever emerges from the frenetic calls and meetings before the summit on June 21, the treaty will be a shadow of the 500-page Constitution which French and Dutch voters rejected two years ago. But it will not be quite as pale a shadow as Britain was expecting, along with the others of the “minimalist squad” who wanted a slimline treaty – France, Poland, the Czech Republic and the Netherlands. Mrs Merkel’s six points threaten to revive parts of the constitution which Britain, to its relief, thought had died.

Dutch and French voters did Tony Blair – and now Gordon Brown – a huge favour in voting “No” in 2005. British voters would never have backed the original constitution, and ministers’ reservations about the prescriptions have since grown. Britain is now demanding an opt-out from the clauses it finds most threatening. Germany will not like granting that but, unlike Poland’s demands, the British ones do not threaten the entire existence of the treaty.

A bluffer's guide to the EU treaty

Our correspondent hacks through the verbiage to explain what happened at the EU summit and what it means

• Patchwork deal proves Europe cannot heal its deepest wounds

Background

• Unconstitutional

• Fresh start or revived constitution?

• Merkel’s dream; Britain’s nightmare

• Brown’s first test: how to avoid an EU constitution

• Europe divided over summit plans

Mrs Merkel’s position, from the start of her Chancellorship 18 months ago, has been to salvage as much as other member states would bear. Her letter to EU members this week makes clear that she has preserved to that ambition. The question is whether, over this weekend, she can hold that ground.

What’s gone

The anthem, flag, and most of the other “constitutional” trappings of the constitution, which set out the EU’s aims and institutions, have probably been junked (although a possibility of their revival flickers through Mrs Merkel’s discussion points). So has the original Part III, a long reprise of existing treaties, and so have most of the original 500 pages. And so has the word “constitution”, now taboo. Instead, the text is an “amending treaty”.

What’s in for sure?

New jobs for those running Europe; on this, countries agree. There will be a full-time president to chair the European Council (the regular meeting of the heads of government). This would replace the six-monthly rotating presidency which, in a union of 25 members, has made continuity hard to achieve, many feel.

There will be fewer commissioners than there are member states. It was becoming unwieldy – and embarrassing – to create new commissioner jobs as the EU expanded.

There will be one foreign minister (although not called that, as member countries do not want any suggestion that their own foreign ministers’ powers will be overridden). The new job will combine those of the Council’s High Representative for foreign affairs, and the commissioner for external affairs.

Status: serene

New voting weights

The big problems start here. Advocates for reform (and for the old constitution) argue that an EU of 25 members or more needs different rules for voting, requiring only a majority, not unanimity, for striking many agreements.

Countries are more or less agreed on the principles of “double majority” voting: requiring 55 per cent of the total number of member states, and 65 per cent of the population.

But Poland wants a formula based on the square root of the population, to minimise the difference between its voting weight and Germany’s. Status: Stormy. The row most likely to bring down the treaty.

Challenger: Poland

New areas of law-making

This is the second-biggest problem, and a lot is up for grabs this weekend. The treaty preserves much of the constitution in extending majority voting to areas where countries previously had a veto.

The most controversial are justice, home affairs, and benefits for migrant workers. Britain wants an opt-out and will probably get it.

One of Angela Merkel’s most controversial “points for discussion” is whether foreign and security policy should be subject to majority voting. In the constitution, this crossed one of Britain’s “red lines”; Tony Blair and Gordon Brown will look frostily on its reappearance.

Status: unsettled Challengers: Britain, the Netherlands, the Czech Republic

Charter of fundamental rights

This is one of the biggest potential rows this weekend. This was the notorious Part II of the constitution, which set out rights that the EU believed its citizens should have. Britain disliked it, fearing that it would enormously extend social and employment rights, and among other consequences, hurt corporate competitiveness.

Mrs Merkel’s letter makes clear that she wants to keep the charter of rights in some form. Given the profound objections of Britain, among others, few expect the text itself to appear in the new treaty. It might be a special protocol, and many countries say they regard it merely as a statement of a common belief in social justice.

But a clear majority has talked of inserting a clause which could give it legal force, which Mrs Merkel would support, although Britain would resist. Status: surprising grip on life after death.

Challengers: Britain, Czech Republic, the Netherlands.

Legal status of the treaty

The treaty is likely to include one clause of the old constitution, which gave the EU a legal “personality” so that it could enter into treaties in its own right. Also up for discussion in the next week is the stipulation that European law has supremacy over national law; some member states will argue that this is redundant, on the grounds that the European Court of Justice established this in the 1960s.

What now?

Mrs Merkel wants EU members to agree on the principles of the treaty at the summit; to hold an intergovernmental conference in the autumn to thrash out the last details; to finalise the treaty by the end of the year; and to ratify it next year, in time for European Parliament elections in 2009.

For and against

Countries who rejected the constitution in a referendum France (55% voted no), Netherlands (62%)

Approved in referendum Luxembourg (56% said yes), Spain (77%)

Ratified in parliament Austria, Belgium, Bulgaria, Cyprus, Estonia, Greece, Hungary, Italy, Latvia, Lithuania, Malta, Romania, Slovenia, Germany, Slovakia

Decision postponed Czech Republic, Denmark, Ireland, Poland, Portugal, Sweden, United Kingdom

At the table

Tony Blair Desperate for a good performance at his swansong summit and a final piece for his legacy jigsaw. Speaking daily with Gordon Brown, who will have to pick up the baton and who dearly wants to avoid the referendum that Mr Blair promised on the constitution.

Angela Merkel The German Chancellor has craftily drawn up the blueprint for the new treaty following weeks of arm-twisting and is determined to get everyone to sign up, securing her status as Europe’s saviour. Her reputation rests on the outcome after mixed success at the German G8.

Nicolas Sarkozy has become Mrs Merkel’s self-appointed Simon Peter to convert the unbelievers. Has one eye on a glorious conclusion to this round of treaty-making at a French summit next year, without the need for another disastrous referendum.

Jaroslaw Kaczynski The Polish Prime Minister is the chief member of the awkward squad and has been hardening his demands as the summit approaches because of fears that Germany is gaining too much muscle. Wants at least a review of the distribution of votes among member states.

Jan Peter Balkenende The Dutch Prime Minister wants to conjure a result that means he, like Mr Brown and Mr Sarkozy, can avoid a referendum after Dutch voters rejected the constitution in 2005. Pushing for extra powers for national parliaments to reject European Commission proposals.

Romano Prodi The Italian Prime Minister and former European Commission chief who has been working closely with Mrs Merkel to keep as much of the constitution as possible, even threatening to form a breakaway group with the other true believers who ratified the original document.

Mirek Topolanek The Czech Prime Minister has teamed up with the Poles as a fully-fledged member of the awkward squad because he wants extra voting weight for his country. Causing a headache in Berlin.

José Luis Rodriguez Zapatero The Spanish Prime Minister faces humiliation if too much is thrown out of the treaty after his country enthusiastically backed the constitution. Has done his best to persuade Mr Kaczynski to come on board, so far to no avail.

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