Lusaka - A leading contender in Zambia's presidential elections, Hakainde Hichilema, on Sunday vowed to review a new "penal" mining tax regime that has spooked investors in the copper-rich nation.
Zambia tripled mining royalties to 20% from 6% on January 1, putting the government at loggerheads with mining firms already buckling under a fall in global commodity prices.
Hichilema, a wealthy businessman and leader of the United Party for National Development (UPND), is seen as a frontrunner in elections on Tuesday, along with the ruling Patriotic Front candidate Edgar Lungu.
Hichilema says he will build an investor-friendly Zambia and review the "terrible, penal" tax if elected to succeed former president Michael Sata, who died in October.
"Anything that damages industry, that damages growth, we will deal with that," the British-educated economist told AFP in an interview.
"One aspect (that is) unacceptable is the introduction of the mineral royalty at 20%, which is basically a turnover tax, it does not recognise the cost of production," he said.
In a sign of the fallout from the new tax regime, Canadian firm Barrick Gold announced last month it was suspending operations at its Lumwana copper mine, and would start laying off workers in March.
"How can any knowledgeable government in today's world impose a tax like that?" Hichilema asked.
Mining companies had an obligation to pay tax, "but if you tax them to a point of death, then you don't know what you are doing," he said
Hichilema likened the government's move to "a dairy farmer who milks his dairy cow until blood comes out and hopes to have milk the following day - there will not be milk, the cow will be dead."
Although he ran third in three previous attempts at the presidency, analysts say he now has a chance at the top job having recently gained support thanks to widening cracks in another opposition party, the Movement for Multiparty Democracy.
Hichilema said he is seeking office in a bid to create "an attractive business and investment operating environment" that is "stable, credible and predictable".
Zambia is the world's seventh biggest copper producer.
Despite its mineral wealth, it is ranked among the world's poorest countries.