Stacey Vanek Smith: European Union leaders have been in an emergency meeting in Brussels today trying to get the 27 member EU states to agree to a plan to bolster the euro and save the eurozone economy. Twenty-three countries did agree to a new treaty — but the U.K. would not.

Here to explain is our own Stephen Beard from Brussels. Good morning, Stephen.

Stephen Beard: Hello Stacey.

Smith: So, Stephen, what’s happened? What have European leaders agreed to and what is the problem?

Beard: It’s probably easier to say what they haven’t agreed to. They’ve failed to agree on a new EU-wide treaty with new rules forcing the 27 EU member countries to keep their public spending under control, and punishing those countries that run up big deficits.

Most of them have agreed to this so-called “fiscal union” — 23 of them, including the 17 that use the euro, are signing up to it. But another two are undecided, and crucially, Britain and Hungary have said no.

Smith: So they got almost all of the countries to agree — can two countries really stop an agreement like that?

Beard: This is where it gets complicated, and potentially very messy. What the 23 countries that want this fiscal union have to do is sign a new treaty between themselves. But — and this is pretty critical — Britain argues they cannot then use all the powerful machinery of the EU — the commission and the court — to police and enforce that new fiscal union.

Here’s the British Prime Minister David Cameron, speaking here in Brussels a few hours ago.

David Cameron: We will insist that the EU institutions — the court, the commission — that they work for all 27 nations of the European Union. Indeed, those institutions are established by the treaty, and that treaty is still protected.

So if Cameron’s right, the new treaty cannot be policed and enforced by the commission and the court, making it a rather toothless agreement.

Smith: Our own Stephen Beard in Brussels. Thank you Stephen.

Beard: OK Stacey.