The South Cotabato provincial government in the Philippines has agreed to amend its environmental law, which clears the way for the stalled $5.9bn Tampakan copper-gold project of Sagittarius Mines.

The amendment reverses a 12-year-old policy that prevented open-pit mining in the province.

According to the Philippines’ Mines and Geosciences Bureau, this removes the final regulatory hurdle for the Tampakan project, which had hit a roadblock since 2010, reported Reuters.

Mines and Geosciences Bureau director Wilfredo Moncano, was quoted by the publication, as saying: “South Cotabato’s local legislative body has voted to lift the provincial ban, clearing the only hurdle remaining in developing one of the largest copper-gold reserves in Southeast Asia.

“All the major requirements to legally support the mining operation has been complied with.”

According to Sagittarius Mines, the Tampakan project, if approved, would be the largest mine in the Philippines. It is also expected to be counted among the largest copper mines in the world, should it be developed.

The copper-gold mine is projected to produce an average of 375,000 tonnes per annum of copper and 360,000 ounces per annum of gold in concentrate during the 17-year period of mining and ore production.

Meanwhile, Kalikasan People’s Network for the Environment (Kalikasan PNE) has slammed the lifting of the ban on open-pit mining. The environmental activist group has urged South Cotabato Governor Reynaldo Tamayo to urgently veto the proposed changes to the provincial environmental code.

Kalikasan PNE national coordinator Leon Dulce said: “Lifting the open-pit mine ban will allow mining projects to destroy life-giving watershed ecosystems within South Cotabato.

“The Tampakan mining project will destroy the Altayan-Taplan River ecosystems in the Quezon Mountain Range, while various coal mining projects are poised to ravage the Daguma Mt. Range.”