Polish-German relations sank to a new low last night as German chancellor Angela Merkel threatened to convene crucial talks on a new EU treaty without Warsaw, writes Jamie Smythin Brussels.
The dramatic move came after Warsaw rejected a Franco-German compromise aimed at overcoming Polish resistance to a new treaty to reform how the EU operates.
"We will try to save the many steps forward which we achieved in the last six months in a common mandate by the other member states for the inter-governmental conference (IGC)," said Dr Merkel's spokesman. "Poland will then have the chance to join the European consensus at the inter-governmental conference in the autumn."
The ICG, to be held in the autumn, is the forum where any draft mandate agreed at this summit would be finalised into treaty form.
The move to ratchet up the pressure on Poland followed a day of extraordinary tension at the EU summit in Brussels, where Dr Merkel attempted to cajole Polish president Lech Kaczynski into accepting a face-saving deal.
However, after more than 24 hours of negotiations, German patience ran out when the Polish president's brother, prime minister Jarolsav Kaczynski, went on Polish television in Warsaw and rejected the compromise proposal, saying the talks had "hit a wall".
"The lack of any willingness to back down is very clear on the side of our partners, and I am afraid there may be no way out . . . I am very sorry about that," Mr Kaczynski said.
The threat by Germany to convene an IGC without Poland - one of the EU's biggest states - highlighted the depth of frustration felt by Dr Merkel, who EU diplomats said had bent over backwards to meet Polish concerns.
Warsaw had also enraged Berlin this week over repeated comments invoking Germany's wartime past.
Convening an IGC without the agreement of a member state is not without precedent. An IGC was convened to work on the Single European Act 1986 without the agreement of Britain, which eventually accepted the treaty.
The threat to isolate Poland by Germany was combined with last-minute attempts by French president Nicolas Sarkozy and British prime minister Tony Blair to broker a compromise. Both leaders engaged in telephone diplomacy with the Polish prime minister in Warsaw to try to get him to back a carefully crafted compromise.
The compromise sought to address Warsaw's sole concern at the talks, the so-called "double majority" voting system that is based on population size. This system would weaken Poland's voting weight in EU decision-making vis-à-vis Germany when compared to the current voting system under the Nice Treaty.
To address Polish concerns, Dr Merkel proposed delaying the introduction of the new voting system until 2014, and adding a mechanism that would enable smaller EU states to delay unfavourable decisions.
Thrown into the compromise package was a promise to give Poland several extra members of the European Parliament, and additional protocols added to the new EU "reform treaty" that would boost energy solidarity in the Union.
The Germans also offered Britain several new elements in a new draft treaty to alleviate concerns in London that it would undermine national sovereignty. These included giving Britain the ability to opt out of EU justice decisions - a measure that will also be available to Ireland - if it felt that it threatened the common law system.
Dutch concerns were also addressed in the compromise text, which would form the basis of technical negotiations on a new treaty at the autumn IGC.
EU diplomats last night predicted that if no breakthrough could be achieved in the late-night talks, relations between Germany and Poland would sink to post-war lows.