Spain's nuclear regulator on Monday blocked Berkeley Energia's planned uranium mine in the west of the country on safety concerns, in a move that was welcomed by environmental campaigners and sent the company's stock plunging.
The CSN regulator said it took the decision due to a lack of reliability and a high level of uncertainty over how radioactive waste would be stored at the facility.
The London-headquartered company, whose Madrid-listed shares slumped over 12% to 0.34 euros, said in a statement it refuted the CSN's assessment and was disappointed with the decision.
"The Company will strongly defend its position and will immediately consider the range of legal options available to it," it said.
The Stop Uranio environmental protection group, which has been campaigning against the mine's development, welcomed the decision.
"After a decade of mobilising, we start to see the light at the end of the tunnel with a decision based around technical criteria," it said.
Berkeley's Retortillo project in the western region of Salamanca received preliminary approval in early 2013 but has since faced local opposition.
Reuters reported in 2018 that the government would not grant Berkeley the necessary permits to operate.
The company had said the mine would run for 14 years, generating investment of over 250 million euros ($297 million)and more than 2,500 jobs in the region.