Plans for the summit, which is likely to be held in Maastricht, crystallised in the sidelines of an EU foreign ministers' meeting in the Dutch coastal resort of Noordwijk yesterday.
The plans reflect the fact that Britain's partners have given up negotiating with the Conservatives on the future of Europe.
The Irish Foreign Minister Dick Spring summed up their exasperation with Britain yesterday. "They are not in a position to demand anything because they are against everything" he said.
Among themselves, the 14 are slowly narrowing down a series of possible trade-offs on wide-ranging reforms to the Maastricht Treaty.
They are anxious to pin down Mr Blair at the earliest possible opportunity, in order to salvage stalled treaty-review talks and produce a new pact when they meet in Amsterdam three weeks later.
One diplomatic source said that the Tories, who have been blocking progress on all but the most marginal reform ideas, have been "written off" as serious partners since the election campaign kicked off.
The idea of a special summit with a new Labour Prime Minister - if he wins - is to give him a first-hand account of the nature of the deal which is being put together, the official said.
"Tony Blair will have to be shown the books," he said.
The Labour leader will be asked to address proposals which remain deadlocked after Noordwijk, but on which foreign ministers believe deals can be done over the coming weeks.
Labour has already indicated that it would maintain the Conservatives' opposition to the scrapping of national borders and to a future merger between the EU and Europe's defence body, the Western European Union.
Both issues pose difficulties for other member states, so Mr Blair does not risk isolation. He also has a good chance of securing an opt-out from moves to create a passport-free travel zone for EU citizens.
Deals on these issues could be facilitated if, as suggested, Labour withdraws the Government's demands for treaty changes to outlaw fish quota hopping and the use of safety and health provisions to legislate for conditions in the workplace.
EU diplomats believe that on virtually every other issue Labour are willing to negotiate. These include:
The Social Chapter opt-out. Labour have made it clear they will sign up to the Social Chapter but they will also be asked to agree to a legally binding chapter in the new treaty on employment. The latest Dutch proposals have been rejected out of hand by the Conservatives because they would give the European Commission a role in co-ordinating and initiating measures to tackle job creation. Britain could be ordered to take steps deemed necessary by Brussels to meet annual unemployment targets and would enjoy no right of veto.
Qualified Majority Voting. Labour are likely to back moves to scrap the national veto in a handful of areas, such as legislation on the environment or industry, but not on taxation or constitutional questions, which is not being proposed. Mr Blair will, however, strenuously resist proposals to extend majority voting to co-operation on judicial matters, immigration or foreign policy.
Size and powers of the European Commission. Britain would lose one of its two European Commissioners if proposals to cut the size of the 20 member executive to 15 win acceptance. This would mean that either Sir Leon Brittan or Neil Kinnock, Britain's two commissioners, would lose their seats.
France looks likely to be defeated over its demands for a Commission with a maximum of 10 members, but there is still the possibility of a two-tier structure in which some Commissioners would be given more influence than others. Mr Blair would have to decide whether to sacrifice one British commissioner, and whether to exact a price, in terms of more voting strength for Britain in the Council of Ministers. Labour will have to decide whether to back strengthening the powers of the European Commission president, which is on the cards.
Votes in the Council of Ministers. A British Labour government could be expected to line up with the other big nations in demanding a fairer re-weighting of votes in the law-making Council.
Taking population into account would seriously tilt the balance in favour of the bigger member states but is considered essential by France ahead of EU expansion to the East. The latest indications are that most governments will opt to postpone a decision on the Council votes until enlargement has taken place in the early years of the next millennium.