A strong 'yes' vote in France should settle things for the moment, though it leaves the Danish question unsolved. But if there is a 'no' vote, the last thing that politicians want to do is give the impression that the EC has entered a period of chaos. And, as a British official pointed out, there is a third option: if the treaty gets a slim 'yes' vote in France, that would also create a crisis.
A narrow majority would lead to demands for a referendum in Britain, and create further financial instability. Some officials said that Maastricht might have to go anyway, since confidence in it has been so weakened. 'Whether it's a 'yes' or a 'no', renegotiation could be up for grabs,' said an official of an EC country.
In the event of France rejecting Maastricht in Sunday's poll, what appears likely is a declaration from New York, where foreign ministers will meet. It would set out the existing foundations of European integration - the single market, co-operation on foreign affairs, the European Monetary System.
This would probably be accompanied by an affirmation that integration would continue in some form, with a 'cooling off' period. There would have to be talks about what parts of the treaty - if any - could be salvaged before next year, when the treaty was due to come into force.
In either case, the most urgent need will be to stabilise the situation. But planning for post-Maastricht is highly complicated. Three sets of options were present in comments made by ministers and their spokesmen in Hertfordshire. First and foremost was what might be called the chaos theory. 'When there is an earthquake, you cannot tell how the houses will fall down or how the ground will open up,' said Roland Dumas, the French foreign minister.
Jacques Delors, President of the European Commission, said that 'attempts to start again will just be window dressing'.
Given the political cost to both men of a Maastricht defeat, their despair is hardly surprising.
Douglas Hurd, the Foreign Secretary, was rather more sanguine. 'After an earthquake, life goes on,' he said crisply. He would not comment on suggestions that a new inter-governmental conference may have to be convened. He would only say that Britain would, in the event of a defeat, be 'activating and bringing forward a Community perspective as well as our own'.
The difference between the two might well be a problem. Britain holds the presidency of the EC and would play a key role in the next steps, yet is sharply at odds with many of its partners over how the EC should work.
Britain appears to believe that parts of the treaty can be resuscitated - those where agreement between governments is the rule, and the EC institutions, such as the Commission, are less involved.
Mr Hurd would only say that following a defeat, there would have to be a rethinking of the EC. 'To what extent that needs to take treaty form . . . is something that we need to discuss,' he added.
The third option is that pressed by the EC's more federalist states, such as the Netherlands. Hans van den Broek, the Dutch Foreign Minister, said: 'I can't believe we can just put Maastricht in a drawer and continue as normal. The process of integration will have to go ahead.' Dead or alive, the Maastricht treaty presents huge problems. Alive, it contains parts which some countries liked, demanded even, but other nations want dropped. That is in its nature: it was a historical compromise. Once it falls off the perch, things may get worse, with some states demanding that sections are revived, and others insisting they were the cause of all the trouble.
The biggest question mark is that hanging over monetary union. A detailed blueprint for uniting Europe's currencies was drawn up at Maastricht, and it would die with the treaty. The weekend's events show how closely integrated the EC's financial systems are. If they do not carry on with plans to converge their economies, as planned in Maastricht, can the existing European Monetary System survive?
Mr Van den Broek said that the Netherlands attached particular importance to monetary union. There are strong hints that those states, such as the Netherlands, already tightly bound to the Bundesbank, may push for more rapid monetary union, with a smaller club.
Given the damage done to the credibility of every government which signed Maastricht, the political atmosphere for any new negotiations would be sour. And the political aftershocks of Mr Dumas' earthquake would go far beyond the treaty.
Mr Van den Broek said that unless plans for unity were agreed, enlargement of the EC could be put on hold. Poland, Hungary and Czechoslovakia have appealed to the EC to ratify their association agreements by the end of this year and a Polish diplomat said there was concern that delays would result.
An EC official said on Sunday that 'a host of emergency meetings will have to be held before the end of the year', creating a climate of permanent instability - an earthquake that does not end.