BOGOTA: Colombia’s government will seek congressional approval to harmonize national and local mining laws, the mines and energy minister said on Monday, as legal wrangling over environmental regulations and community opposition threaten investment.

Voters in central Tolima province last month backed a proposal to ban mining projects in their municipality, raising questions about the future of an AngloGold Ashanti Ltd gold exploration in the area. Canadian company Eco Oro Minerals Corp, meanwhile, is waging a legal battle against a court ruling that bars exploration in half its concession.

The Tolima vote was made possible by a Constitutional Court decision that overturned the national government’s sole authority to approve mining projects, allowing mayors and provincial governors to challenge exploration permits, to the delight of environmental groups and some politicians.

The move caused uncertainty among investors in Colombia, the world’s fifth-largest producer of coal with rich reserves of gold, ferronickel, silver, copper and emeralds. The government hopes the law would ease concerns by clarifying how land use disagreements between local and national authorities would be resolved, Mines and Energy minister German Arce said in an interview.

“It’s a very in-depth discussion that we’re having - how to harmonize the different legal mandates, because mayors have the power to organize land but the national government administers the subsoil,” Arce told Reuters.

“We have a project that we are discussing with Congress - it’s not formally presented yet - where we will define how to handle it,” he said.

“Giving a clear rule to investors will take away part of the uncertainty that’s been created by the activism of a few tribunals and courts and by the referendums,” Arce added.

AngloGold and Eco Oro did not immediately respond to requests for comment.—Reuters