British diplomats were putting the chances of securing such a framework by Florence at "only 50-50". John Major has urged European Union member states to agree a framework before the meeting, which starts in 10 days, in return for an end to Britain's policy of disruption.
Meetings to negotiate the deal take place in Brussels on Friday and in Rome on Monday. Everyone recognises that without a framework, the summit, which concludes the Italian presidency, could be undermined by the British veto, causing lasting harm to British-EU relations.
On the face of it, the British proposals are uncontroversial. The idea is to secure an agreement in principle from member states for a 10-step phased lifting of the ban. There is no proposed timetable for the process and each element of the ban would be lifted on the basis of a European Commission proposal, which itself would be based on scientific advice.
However, in the framework document Britain is also seeking to bind member states to agree in advance not to block future decisions to lift elements of the ban.
Under procedures applied to lifting the ban on gelatine, tallow and semen, it was the Commission which decided to make a proposal to ease it, based on scientific evidence. But the proposal failed to win a qualified majority vote in the EU's standing veterinary committee or in the agriculture ministers' council, causing long delays. In the end, the Commission had to implement the measure unilaterally under EU procedures.
Since then, it has indicated it would not act again without political support of member states. So it is important for Britain to prevent member states blocking a future Commission proposal. British officials accept they cannot force member states legally to give prior commitment not to vote in a certain way. But by winning prior agreement on procedures, it would be more difficult for member states to block in future, they argue. To most member states, however, the British demand looks like an attempt to tie their hands.
To try to break the impasse Britain will over the next few days try to negotiate more detailed criteria for the lifting of each phase, to give more reassurance to other member states that they are not signing a blank cheque. The criteria will be discussed on Friday for the first time by the veterinary committee before a "conclave" of foreign ministers in Rome on Monday. But few believe the process can be completed in time for Florence. Britain can only hope other member states will make concessions in their desire to preserve the summit.
Jacques Santer, the European Commission president, who is trying to broker the agreement, said he was "quite confident" of success before Florence. But senior Commission officials privately said there was "no way" member states would agree to the terms Britain was offering.
Germany in particular still opposes any new commitments on easing the ban. And John Bruton, the Irish Prime Minister, who has spoken to Mr Major, Mr Santer and to Helmut Kohl, the German Chancellor, in recent days, spoke yesterday of a "gulf of misunderstanding" between the sides.