There are huge gaps in the Commission's outline. When is the start date of the slaughter programme? What is the phasing? Are more cows to be brought in? Are there binding reassurances from our partners for lifting the ban? And, crucially, how are farmers to be compensated?
The summit will answer these questions, and the Prime Minister will have to decide whether or not he agrees with the answers. So by tomorrow evening, we will be able to see the final deal and judge whether what the Europeans have dubbed "the war of Mr Major's mince" has been worth the fight.
There are three possible outcomes:
Outcome 1. Beef in our time
Mr Major returns from Florence waving a piece of paper. He declares this a brilliant and decisive victory. The paper contains an agreement, agreed by our partners, which is binding, fills the gaps to Britain's satisfaction, provides for the phased lifting of the beef ban at specified dates and enacts a package of measures that will convince the citizens of Europe that British beef is safe to eat. This was what Mr Major said he wanted when he suddenly launched his policy of confrontation on 21 May.
Since then however, the Government has been busy moving the goal posts. And understandably so. For the policy of confrontation has been entirely counter-productive, hardening attitudes to Britain's case and making it more difficult for our friends to help us get out of this mess.
It is now quite clear that there is nothing that will emerge from Florence as a result of this policy, which could not have been much more easily achieved without it - and without the damage it has caused to Britain's respect abroad, to our influence in the future and to our agricultural industry at home. Indeed, it may well be that even more healthy cows will have to be sacrificed because of the delays and confusion caused by Mr Major's destructive tactics.
But the Europeans know that this goes much further than cows. If confrontation wins over co-operation this time it will be tried again - and not just by Britain - in the future.
Which is why "beef in our time." is the least likely outcome of Florence.
Outcome 2. C'est magnifique, mais ce n'est pas le boeuf
Mr Major returns from Florence with a fudge. He declares this a brilliant and decisive victory. The package is, broadly, what the Commission has now proposed, Britain kills lots more cows, perhaps 70,000 more. But we obtain in return only a vague framework stretching into the blue distance of an indeterminate future. Nothing is binding, no firm steps are required by our partners abroad, but every step we take in Britain must be inspected and validated by the Commission.
The Euro-sceptics, who know they have Mr Major's head in a noose, will probably riot. And farmers, who know that this deal will do real long- term damage to Britain's milk industry without getting anything bankable in return, may well do the same. The combination could be deadly to the Government's majority in the House of Commons.
Outcome 3. The long, slow, humiliating retreat of our beef expeditionary force from Europe
Mr Major returns from Florence without any agreement. He declares this a brilliant and decisive victory. The policy of non co-operation then drags on and on with Britain looking more and more ridiculous, opposing the things we want and have been fighting for in Europe. Meanwhile, under cover of a government propaganda barrage, we are, in reality, beating a disorderly and miserable retreat that ends with Mr Major, on the white cliffs of Dover, saying, "Very well then, alone" and calling a general election.
I can think of no better epitaph for this Government than that it should be brought down by mad cows. But the real damage being done to Britain is not funny at all and extends well beyond cows.
The BSE affair is being viewed by our European partners as a watershed. Until now they were prepared to spend time and energy to achieve compromises that kept Britain on board. Now they are talking of "giving up on Britain" and of "building a four-lane bypass" around the British road block at the forthcoming Inter-Governmental Conference. They quote Mr Major's Leiden speech of September 1994, in which he said that it was "perfectly healthy for all member states to agree that some should integrate more closely and more quickly in certain areas" and his many statements since that if others wanted to do this, Britain wouldn't. Many Europeans have concluded that it is now time to take those sentiments at face value and put the proposition to the test.
There are even secret conclaves of Brussels lawyers discussing dividing the Commission in two, with one part serving a core Europe of the strong countries and the other looking after the outer ring of Europe's weaker countries, those new democracies making their way towards Europe's core - and, of course, Britain.
This is why, in the short term, Florence could decide Mr Major's future. In the long term, it could decide Britain's, too.
The writer is Leader of the Liberal Democrat Party.