The claim

“That [a deal between the 17 euro members] simply is not possible under the European law. He [Cameron] shouldn’t accept it. Of course he should draw the line.”

David Davis MP and former Europe Minister, Radio 4 Today programme, 8 December 2011

Cathy Newman checks it out

For the eurosceptics, David Cameron has a golden opportunity tonight in Brussels. They argue that Merkozy’s cunning plan to rescue the eurozone has to be agreed by all 27 European Union members.

And they want the prime minister to play hard ball by saying non and nein, unless he gets something back for the UK in return.

But can the 17 eurozone countries stick two fingers up to Britain, and agree a deal without our say-so?

That certainly seems to be what Nicolas Sarkozy and Angela Merkel are threatening. But do they have une jambe or even ein bein to stand on?

The analysis

France and Germany are hoping all 27 EU members will agree to their EU reform treaty at tomorrow’s summit. It proposes tougher rules and sanctions, in the hope of generating confidence in the 17 eurozone countries and securing the single currency.  It might be a deal to save the 17, but because it’s a treaty change, all 27 EU countries have to agree to it.

As David Cameron thrashes out the details, many are calling on him to use his power of veto to get us good deal. But if they can’t all agree – is there any chance the 17 euro members could do it without the other 10?

David Davis hit the airwaves to insist that the PM should put his foot down if the 17 even try tabling a deal outside the EU.

All Cameron has to do is “point out the legalities”, Davis said, adding that the idea of a plan that didn’t include all 27 members was “not feasible”.

Is he right or could the 17 go it alone?

It is of course not illegal for the 17 euro members to enter into an international agreement – they are free to make deals between themselves. But, the big question is: how would they do it without the institutions and mechanisms of the EU?

The 17 would want to use the European Courts of Justice, the European Commission and all the other institutions that help police Europe. To use any of these, they would need the permission of all 27 EU members.

As the Foreign Office told FactCheck: “Whilst the content of an intergovernmental treaty at 17 is a matter for the 17 signatories, it cannot cut across the provisions of the existing EU Treaties nor can it seek to use the EU institutions without the specific agreement of all the EU 27.”

Without the agreement of the 27, they would have to set up their own legislative body.

Davis said the idea of having something completely separate to the operation of the Union would be “very odd”. He added: “You’d have to create an entirely new structure”.

And indeed, Paul Craig, Professor of English Law at Oxford University, told FactCheck: “The bottom line is we’ve not yet seen any plan worked out, by which the 17 could do something which would NOT involve the European Commission, the Court, Parliament and Council.”

Mats Persson, director of the think tank Open Europe agreed. “Outside the (EU) institutions it is very unclear who would enforce it (a deal between the 17). Ideally the European Commission would be charged with policing the rules (which would require agreement from the 27) – then if they were abused it would be automatic for the Commission to take action,” he told us.

Prof Craig added: “Although things have been batted around about the 17 doing it without a treaty change – how? I’ve not seen anything yet. David Davis is right in that respect.”

There is only one thing that could muddy the water and that is the chance that the 17 could do a deal within the existing rules of the Lisbon Treaty – and so throwing out the need to change the treaty.

Professor Craig however said this was “doubtful” and pointed out that the Germans themselves don’t even believe this is possible.

Does this mean we’ll have a referendum?

So if the treaty is set for a change and the UK has to agree to it as one of the 27 – are we in for a referendum? Not necessarily.

As FactCheck wrote earlier this week, any treaty change would only trigger a referendum if it saw UK powers transferred to Brussels.

The new European Union Act, passed by the coalition in July, sets out a huge list of changes that would automatically kick off a referendum. “The drafting is very “British”. Nothing is left to chance. Every conceivable form of Treaty change is exhaustively delineated,” Professor Craig wrote in this month’s Common Market Law Review.

David Cameron continues to insist that no “significant transfers of power” have been discussed. And he’s already blocking those that might – today he opposed an EU wide tax which would affect London and the UK.

Cathy Newman’s verdict

David Davis is right – so theoretically David Cameron could drive a hard bargain over dinner tonight.

The problem is, the PM has judged that because of our economic reliance on the rest of Europe, Britain’s best interests lie in us agreeing the eurozone deal not thwarting it.

And that has angered eurosceptics from David Davis right to the top of the government.

No doubt Cameron will try to bring something back worth shouting about, but don’t bet on it being anywhere near enough to satisfy his disgruntled party – or stave off calls for a referendum.

The analysis by Emma Thelwell