Tens of thousands of Bulgarians downed tools and blocked roads on Thursday to protest against government plans to phase out communist-era wage benefits and make firing workers easier. The protests come as the EU candidate gears up for general elections next year, piling pressure on Prime Minister Simeon Saxe-Coburg's ruling NMS party which trails behind the opposition Socialists in opinion polls. Workers burned tyres and blocked the country's main highways in demonstrations that drew tens of thousands of coal miners, teachers, and transport and factory workers. "We've got three possibilities. The first is dialogue, the second is protests and rallies, and the last is a serious nationwide strike," said Konstantin Trenchev, head of Podkrepa, strike co-organiser and Bulgaria's second largest union. "If we don't get a response, we'll decide what to do next in the coming days," he said. Unions said 400,000 workers in the country of 10 million took part in various protests -- some of which lasted less than half an hour. The interior ministry said it could not confirm the figure. The goverment, backed by many economists and the IMF, argues that labour reform is necessary to spur investment and employment and make the economy more competitive on the threshold of EU membership, due in 2007.