German Chancellor Angela Merkel on Friday warned she would launch negotiations on a new "reform" treaty for the 27- nation bloc even if Poland refuses to give its go-ahead to the deal, German spokesman Ulrich Wilhelm said, according to dpa. Wilhelm said Merkel told EU leaders she intended to table proposals for a mandate to open inter-governmental negotiations on a new treaty "without Poland" if necessary. The chancellor was reacting to a new threat to veto treaty talks made in Warsaw by Polish Prime Minister Jaroslaw Kaczynski. Poland is represented at the EU summit by President Lech Kaczynski, the premier's twin brother. Wilhelm said the German EU presidency made repeated attempts to address Polish demands for an increase in its voting rights in the EU's decision-making council of ministers. The German offer had been "far-reaching" but had been rejected by Poland, he said. Merkel could not accept that the EU stand still, said Wilhelm. Progress achieved over the last six months must lead to the start of inter-governmental negotiations on a new treaty, he said. Poland had the opportunity to join the talks if it wanted, said Wilhelm, adding that from the legal point of view, a majority of EU leaders could decide on a mandate for the negotiations. Speaking in Warsaw, Polish Prime Minister Kaczynski once again threatened to veto a summit deal, saying no concessions on key provisions were being made "on the other side." "We can't keep on backing down," he said, adding: "Poland is too important country in Europe for it to have to give up everything." The Polish threat came as the EU summit entered a decisive end- game Friday evening, with Germany unveiling new compromise proposals aimed at meeting Poland's demands on voting rights. The German offer included suggestions that the current system for distributing decision-making votes in the bloc, agreed 2000 at a summit in Nice, should be extended until 2014. Under the deal, Poland with 27 votes is almost on a par with big EU states Germany, Britain, Italy and France, which have been accorded 29 votes each. The German proposal would delay by seven years the introduction of an EU "double majority" voting scheme, which requires that EU decisions have the support of 55 per cent of member states, representing 65 per cent of the population. Poland opposes the scheme, saying it gives too much clout to the EU's bigger states like Germany. The German offer also includes a proposal by French President Nicolas Sarkozy allowing a small group of countries to use an emergency brake to block decisions they do not like, even if they do not meet EU criteria for forging so-called blocking minority. The new EU rulebook is designed to replace the draft constitution rejected by French and Dutch voters in 2005. 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. The new German compromise text also seeks to persuade Britain to lift its "red lines" on issues such as the appointment of a first- ever EU foreign minister. Leaders agreed the new treaty would instead refer to an EU "high representative for foreign policy" - already the job title for Javier Solana, the current EU chief diplomat. However, unlike Solana, the future EU "high representative" will also be a vice-president of the European Commission, the bloc's executive arm. In addition, he or she will be backed up by an EU diplomatic service including commission officials and diplomats from national governments. Britain opposed the title of "foreign minister," arguing that this gave the impression that national governments were ceding sovereignty in the crucial foreign policy area to the EU. The summit is expected to endorse British demands for opt-outs on EU justice and police affairs as well as issues related to social security. The new treaty will also make clear that while a charter on fundamental rights will be legally-binding, it will not impact on Britain's labour laws. Diplomats said a decision to drop a key reference in the new treaty to the bloc's commitment to "free and undistorted competition" did not appear to be causing major problems. The treaty wording, reflecting a demand by Sarkozy, initially provoked a backlash by Britain and other EU free-market states which said promotion of free competition was a core objective of the bloc. However, EU officials said that although competition may not be mentioned in the preamble, the treaty itself had up to 13 references to free competition within the bloc. Therefore the move would have no "legal implication," said one EU official.