"The German chancellor wants to take a decision at the summit without Poland," said Merkel's spokesman Ulrich Wilhelm in Brussels.
"The German presidency now wants to obtain a joint mandate of the 26 other countries for an intergovernmental conference (IGC)." he said.
The goal of the IGC would be to draw up a new treaty instead of the bloc's constitution, which was rejected by French and Dutch voters in 2005. According to EU regulations, a simple majority of countries is needed to call such a conference. Any decisions reached at the conference, however, would have to be unanimous.
"Poland would then have the chance to join the European consensus at the governmental conference in the autumn," Wilhelm said.
Polish opposition to the "double majority" voting scheme, requiring that EU decisions have the support of 55 per cent of member states, representing 65 per cent of the population, has been one of the key stumbling blocks in efforts to strike a treaty deal.
Poland sees it as less favorable to medium-sized nations than the current voting share-out under which it has 27 votes, almost on a par with big EU states Germany, Britain, Italy and France, which have been accorded 29 votes each.
A failed attempt?
In an effort to end the ongoing impasse regarding EU voting rights, Merkel on Friday offered new concessions to Poland as European Union leaders entered a decisive end-game at summit talks in Brussels.
Jo Leinen, chairman of European Parliament's constitutional committee, said Merkel had told the Polish delegation that application of the EU's "double majority" system for decisions would only be introduced in 2014, instead of in 2009 when the new "reform" treaty is expected to come into force.
This offer was, however, quickly turned down by Poland's Prime Minister Jaroslaw Kaczynski.
"If you ask me now, I'd say that the negotiations are going to end with a veto," Kaczynski said in an interview with Poland's public TVP1 broadcaster.
"What's been proposed to us is not enough for us to be able to accept," he added.
Merkel was also seeking to ease Polish concerns through the introduction of a mechanism allowing a small group of countries to stop unfavorable decisions -- even if they do not meet current EU criteria for forging a so-called "blocking minority."
Wilhelm said the German EU presidency made repeated attempts to address Polish demands and that the German offer had been "far-reaching." In the light of the Polish rejection, however, Wilhelm quoted Merkel as saying it was important to take action to avoid "leaving Europe to mark time."
No EU foreign minister?
In a concession to Britain, Germany agreed that the EU's charter on fundamental rights would only be legally binding in areas covered by EU laws. This means it would not apply to Britain's labor legislation.
In addition, as demanded by Britain, the treaty will not refer to the appointment of a first-ever "foreign minister" but to a "high representative for foreign and security policy," which is already the job title held by Javier Solana, the EU's current chief diplomat.
Britain claims that the title of foreign minister would give the impression that national governments were ceding sovereignty on foreign policy to the EU. The newly proposed high representative, however, would also serve as a vice-president of the European Commission, the bloc's executive arm.
In addition, the new foreign policy post would be backed up by an EU diplomatic service including commission officials and diplomats from national governments.
The summit, chaired by Merkel, was scheduled to end later on Friday. But diplomats said discussions could stretch out into Saturday to give leaders more time to break the deadlock.