BRUSSELS (BBC) - Germany's chancellor is stepping up efforts to broker a compromise with Poland over a draft treaty to replace the failed EU Constitution.

Angela Merkel met Polish President Lech Kaczynski three times in 12 hours, in a bid to overcome objections to planned changes to the EU voting system. So far no deal has been reached but Polish officials say they are putting forward a "last-chance" proposal. The original treaty perished when Dutch and French voters rejected it in 2005. ---------Red lines The German chancellor, who holds the EU presidency until the end of June, has held one-on-one meetings with the leaders of Poland, the UK, the Netherlands and Czech Republic, in a bid to overcome objections to how the EU should be run. "We're working hard. The problems are not yet solved but everyone is trying," said Ms Merkel. Various solutions have been offered to try to overcome Poland's objections to the new voting system, which Warsaw says would give too much influence to Germany. There was alarm in some quarters after the Polish president said the reason his country did not have a larger population - and therefore greater voting power - was that so many Poles were killed by Germans in World War II. British Prime Minister Tony Blair - attending his final EU meeting before leaving office next week - has set out a number of "red lines" beyond which he will not compromise. These include proposals to make the EU Charter of Fundamental Rights legally binding. Britain also wants to maintain national control over foreign policy, justice and home affairs. In a last minute complication, the UK and others asked for clarification on why a key reference to the EU's commitment to free competition had been dropped from the draft treaty at the request of the French. "The notion that this in any shape or form changes the legal basis of the internal market and the way the European economy works and the Commission's powers in relation to it is wrong," said Blair, adding that a protocol would be added to the treaty. ---------Fresh crisis There has been broad agreement on the job title of a new EU foreign policy chief. The post-holder will not be called a minister, as in the European Constitution, but High Representative of the EU, and will combine the job of the vice-president of the European Commission, which comes with a significant aid budget and staff. Leaders have also agreed to allow Cyprus and Malta to adopt the European single currency, the euro, beginning in January 2008. The BBC's Oana Lungescu in Brussels said the Germans are expected to table new proposals and, according to one diplomat, there was some optimism a compromise formula could be agreed over dinner. The document makes several concessions to EU member states that had opposed key parts of the planned constitution. ----------Proposed changes include: Removing any mention of the word "constitution" Providing countries with a chance to opt out of EU policies in the area of policing and criminal law New voting system to approve decisions Full-time president of European Council instead of current system where members take six-month turns New foreign affairs head and a smaller commission Correspondents say failure to reach a deal on the treaty would plunge the EU into a fresh crisis as deep as the one that followed the rejection of the constitution two years ago