BELGRADE, Nov 24 (Reuters) - About 2,000 protesters rallied in Belgrade on Wednesday over the planned adoption of laws on expropriation and a referendum they say is designed by the government to help investors speed up their mining projects in Serbia. The protesters rallied in front of the office of President Aleksandar Vucic and later marched through the city centre. Serbia is one of Europe"s most polluted countries and will need billions of euros to meet the European Union"s environmental standards if it wants to join the bloc. To speed up economic growth, Belgrade has offered mining resources to foreign companies, including China"s Zijin copper miner (601899.SS) and Rio Tinto (RIO.L), despite opposition by some residents and environmentalists who say ore exploration would further increase pollution. Rio said it would adhere to all domestic and EU environmental standards at its lithium mine in Serbia worth $2.4 million. read more Many in areas slated for mining and infrastructure projects refused to sell their property and went to court, seeking higher compensation in legal proceedings that could last for months. The draft law on expropriation is due to be debated in the coming days in parliament, which is dominated by an alliance loyal to Vucic. It envisions a deadline of up to eight days for the expropriation of property by the state. "People ... will no longer have the right to seek just compensation in court," lawyer Bozo Prelevic told the protesters. Activists have said they will block major highways around the country if the law is adopted. Vucic, under fire for supporting the Rio and other mining projects, told reporters the law would prevent people from seeking compensation that is much higher than market prices. Activists also protested against the draft law on the referendum. Vucic said in June a referendum would be held to allow people to decide whether the Rio lithium project should go ahead.