BHP Group’s bid to spin off Anglo America’s South African assets as part of a takeover proposal shows how the economic policies of the ruling African National Congress (ANC) have undermined investor confidence in the country, the main opposition party said.

The offer by BHP envisages Anglo offloading majority stakes in Anglo American Platinum, the world’s largest miner of the metal by market value, and Kumba Iron Ore to shareholders. Anglo on Friday rejected the £31.1-billion proposal by BHP because it “significantly undervalues” the company.

South Africans head to the polls next month in an election in which the ANC is at risk of losing its national majority for the first time since coming to power three decades ago. It’s hemorrhaging support because of voter dissatisfaction with its management of the economy, including the collapse of state rail and port infrastructure that has hampered mining exports.

“You cannot force a business to do business with you or stay in your country or in your jurisdiction,” Dion George, shadow minister of finance for the Democratic Alliance, said at a briefing in Johannesburg on Friday. “This a very sorry indictment of what we have under the ANC government’s failed and misguided economic policy.”

South African Mineral Resources and Energy Minister Gwede Mantashe, who also serves as the chairman of the ANC, signalled his opposition to the proposal.

“I wouldn’t support it,” Mantashe said by phone on Thursday. “I don’t think Anglo will agree to that. I wouldn’t if I was on the board.”

South Africa’s mining industry is already in a fragile state in a country with one of the world’s highest unemployment rates. Platinum mines, including those owned by Anglo’s subsidiary, either have already cut thousands of jobs or are considering following suit. The upheaval that may result from a successful takeover by BHP, which has divested from the country, adds another concern for labor unions even if the shares in the iron ore and platinum units would be distributed among Anglo’s existing shareholders under BHP’s rebuffed proposal.

Ultimately, whoever ends up owning Amplats and Kumba will have to interact with underperforming State-owned power company Eskom Holdings and port and rail company Transnet. Both have impaired mining productivity, from unreliable power supply to a lack of trains to move mineral exports.

“If you look at the political landscape of the country itself, it’s not giving any confidence to any person,” said Joseph Mathunjwa, president of the Association of Mineworkers and Construction Union, the largest labor group in the platinum industry.

Anglo was founded in 1917 by entrepreneur and philanthropist Ernest Oppenheimer on the back of South Africa’s giant gold mines, before moving into diamonds, platinum and coal. Last year, AngloGold Ashanti — a company formed in 1998 through the combination of Anglo American’s gold assets — moved its primary listing to New York.

“The problem here with the Anglo sale, the reason why they are doing it, is because they’ve lost confidence in our economy and they’re buying forward cover in case we have a massive problem after May 29,” George said.