The institutional issue was first raised two years ago, and there was little evidence then or for most of the intervening months that Britain placed it on the first rank of priorities, or was prepared to go to the wall.
Last September, Britain put forward a paper that considered politically sensitive aspects of the institutional changes that came with enlargement. This included the question of voting. The blocking minority was the key issue: and Britain said it wanted this kept where it was, rather than raised to 27 as other states wanted.
It was evident that it would cause trouble: it raised so many hackles, especially with the small countries. It caused a row in October when discussed by ambassadors and foreign ministers in Luxemburg, but there seemed to be a fairly widespread assumption that this would blow over.
It seemed at first that Britain could expect support from other countries, including France and Germany, two more big states with an interest in preventing the size of the blocking minority from being increased. But there was clearly a difference of opinion in Bonn. While the foreign ministry, and diplomats, said they could see Britain's point, Helmut Kohl, the Chancellor, was moving in the other direction. 'We must not move the church away from the village,' said one German official - meaning that the little countries needed protection for their interests. Mr Kohl is the boss, and his view prevailed.
This influenced France, too, to move away, leaving Britain and Spain the only countries to attach a reserve on the issue when it was discussed in enlargement meetings in November. At the Brussels summit in December, it was discussed then shelved.
It seems highly unlikely that the mood of the other member states was misunderstood. Sir John Kerr, the British ambassador in Brussels, is one of the most respected diplomats in the Foreign Service, and responsible for some of the sharpest compromises and the finest drafting in the Maastricht treaty. His best guess - relayed to Mr Hurd - was that there was a sporting chance of securing some form of closer to Britain's goals.
But by February, it was known that Britain lacked key allies; that time was running out; that enlargement, a key objective stated repeatedly, was at risk; and that the other states were firmly opposed. It is fairly clear that Douglas Hurd had been warning the Cabinet for weeks - and well before the issue started to have the makings of a public crisis - that they might have to compromise. But he was meeting stiff opposition, not all of it from predictable quarters.
In particular, Kenneth Clarke, the Chancellor, appeared a far from reliable ally for the Foreign Secretary despite his instinctive Europeanism and the fact that he supported him in the 1990 leadership contest. He was not a wholly consistent opponent of compromise. He saw for example the force of the argument that a higher blocking minority might help secure reform of the Common Agricultural Policy. But on the whole, Mr Clarke was fairly militant in opposing significant British concessions on the issue. His critics would argue that he was motivated by the need not to seem soft on Europe in case there was a leadership contest sooner rather than later. But as a departmental minister he had had plenty of bruising encounters with Britian's European partners. He likes a fight, so both factors may have been in play. Michael Heseltine, contrary to some reports, has been in recent weeks significantly more with Mr Hurd than with the critics. He lent his backing, for example, to Gillian Shephard, who though normally a critic, urged the CAP argument strongly as a justification for accepting 27.
The other tough nut - though not one of the three most diehard critics, Peter Lilley, Michael Portillo and John Redwood - was Michael Howard, the Home Secretary. While some Cabinet members argued that the 23-27 argument was irrelevant to social legislation, the critics' worst bugbear, since Britain was usually alone in opposing it and therefore only able to command 10 votes, Mr Howard was resistant.
Publicly, he argued, British ministers were saying that the rest of Europe was coming round to its way of thinking on so cial regulation. How then could the Government say that it could not even command the support of one other large country and one small one? As is often the way, Mr Hurd found that the opponents initially argued more vociferously than some of those who backed compromise.
Then the main backbench critics seized the initiative as the negotiations in Brussels moved to their climax. Nearly three weeks ago, Tony Marlow and William Cash raised the issue at the regular weekly meeting of the backbench 1922 Committee. Their intervention, warning that if Britain sold out over the voting issue it would split the party in the run-up to the European elections, set alarm bells ringing through the whips' office; and a new constraint was brought to bear on the long-suffering Mr Hurd.
Addressing the European affairs committee a fortnight ago, he exhorted MPs to realise that they could not expect the issue to be resolved by a straight 23-vote minority or a straight 27 minority. It was the clearest possible signal, though many backbenchers appear not to have read it. Last Tuesday, however, it was blurred when Mr Major used language which inflamed hopes that Britain would simply tough it out even at the risk of delaying enlargement.
All this created the most difficult climate possible for Mr Hurd's trip to Ioannina, Greece, and for the events that followed.