The mine would emply highly toxic cyanide to mine about 300 tonnes of gold and 1,500 tonnes of silver a year.
The lower house of Romania's parliament has rejected revisions to the country's mining laws designed to enable the Canadian mining company Gabriel Resources to construct Europe's largest open cast pit gold mine in the Carpathian mountains. This follows an earlier rejection of the plan on 2 December by the Senate.
Gabriel Resources has been pursuing the project for more than 14 years, and has enjoyed the support of the Romanian Government which has done its best to enable the project to go ahead - and which also has a minority shareholding in the company.
However the mine is deeply unpopular among the country's small farmers and its increasingly vocal environmental movement. The mine would emply highly toxic cyanide to mine about 300 tonnes of gold and 1,500 tonnes of silver a year.
Huge demonstrations and protest actions have taken place in the small town of Rosia Montana, the nearby city of Cluj, and in Bucharest. As MPs assembled for the vote on Tuesday, hundreds of demonstrators chanted "Save Rosia Montana" as they urged their representatives to vote down the legal changes.
This is the second such vote to reject legislation intended to enable the Rosia Montana mine to go ahead. Prime Minister Victor Ponta created a law earlier this year designed specifically for the project, but parliament rejected the bill following powerful protests. The legal changes just turned down represented a 'plan B' following that initial failure.
Gabriel Resources has estimated that the Rosia Montana mine would be worth $5.2 billion to Romania in taxes, royalties, jobs and service contracts. However the figure is disputed by the project's opponents.
Hundreds of protesters gathered before the vote outside parliament as well as in the northwestern city of Cluj, chanting and asking lawmakers to vote against the mining changes.