GORNJE NEDELJICE, Serbia (Reuters) -Zlatko Kokanovic, a farmer from Serbia's Jadar region, is determined to stop development of a Rio Tinto lithium project, identified this week as strategic by the European Commission as it aims to cut dependency on China for mineral resources. 

Lithium is a key component in batteries for electric vehicles and mobile devices. The mine in the Jadar valley would eventually meet 90% of Europe's lithium needs should it go ahead.

But like thousands of protesters, including many other farmers, who have sought to block development of the project in recent years, Kokanovic is worried about pollution of farmland in a region where a majority of people live off agriculture. 

"There are some things the money cannot buy," Kokanovic, a father of five children who is one of the largest milk producers in Gornje Nedeljice and a leading activist in the region, told Reuters. 

"I want to tell them (Rio Tinto) not to try to develop the mine or there will be unrest," he added.

Rio Tinto has not given a start date for the project, which is expected to produce 58,000 metric tons of lithium carbonate annually, but has pledged to develop the mine cleanly.

"The project will be delivered to the highest levels of transparency, to the highest levels of environmental protection and human rights standards," said Chad Blewitt, Rio Tinto's managing director for the Jadar project.

"The European Union and European Commission never substitute, they never sacrifice those high standards." 

Blewitt had told Reuters on Wednesday that the company is revising the cost of the project.

Rio Tinto's lithium project has been contested by green groups for years and sparked massive street protests in EU-candidate Serbia in 2022.

In 2021 and 2022, Serbian environmentalists collected 30,000 signatures in a petition demanding that parliament enact legislation to halt lithium exploration in the country.

The government revoked all Rio Tinto's exploration licences in 2022, before the Constitutional Court overturned the decision last year and reinstated them.

Government officials say the mine will boost Serbia's economy.

How protesters can stop a project that has domestic and international approval is unclear. But recent student protests in Serbia, where hundreds of thousands have taken to the streets and succeeded in collapsing the government, show the strength of civil society in the Balkan country.

Kokanovic remains determined.

"My message to them is not to even try (to excavate lithium in Jadar), unless they want this government to be toppled fast."