Britain threatened on Sunday to veto any deal on the European Union's long-term budget to defend its rebate from Brussels' coffers, which the 24 other members say is no longer justified, Reuters reports. But a crushing regional election defeat for German Chancellor Gerhard Schroeder's Social Democrats, raising the prospect of an early general election this year, made it less likely there would be any budget agreement to veto next month. "Our rebate was justified in 1984 when it was agreed and it is fully justified today, and we will not hesitate to use our veto if necessary," Foreign Secretary Jack Straw said on arrival for budget negotiations with his counterparts. EU leaders are supposed to reach agreement on the 2007-2013 budget at a summit on June 16-17 but positions are far apart. Six big net contributors, led by Germany, the EU's biggest paymaster, have demanded that spending be capped at the current level of one percent of gross national income (GNI) rather than the 1.14 percent proposed by the executive European Commission. --more 2113 Local Time 1813 GMT