Panama’s Supreme Court will consider a lawsuit which alleges that the nation’s contract with copper miner First Quantum Minerals Ltd. violates the constitution.

The court said in a statement that it will issue an opinion on the lawsuit within 10 business days. If it then proceeds, it will request written arguments from attorneys representing both sides. From there, it would advance to the magistrates for a ruling, the court said.

Shares of First Quantum fell in Canada trading after the statement, and were down 4.1% at 12.47 a.m. in Toronto.

The mine is First Quantum’s top money-maker and accounts for about 1.5% of global copper output.

Panama’s congress approved a revised contract with the company on Oct. 20th that grants the company the right to mine copper for 20 years, with the option of an additional 20 years. It also includes a minimum annual payment to the government of $375 million, which President Laurentino Cortizo said will be used to increase pension payments to retirees beginning Nov. 20.

Unions, environmental activists and students say the contract violates the country’s national sovereignty over its minerals and demand a national referendum on the matter. Groups of protesters blocked highways with rocks and burning tires on Thursday demanding the contract be repealed, following a week of street demonstrations against the mine.

First Quantum’s CEO Tristan Pascall said on a call with investors Wednesday that the company is aware of the protests and will work harder at communicating the benefits that mining can provide to communities in Panama.

(An earlier version of this story corrected the headline to say that the lawsuit is against the deal)