S&P Global Ratings lowered South Africa's sovereign credit rating on Monday to a subinvestment grade of BB+, from BBB-, on political and institutional uncertainty. It has also sustained its “negative outlook” on the country.

The downgrade was in direct response President Jacob Zuma’s Cabinet shuffle, which took place at midnight on March 31. The ratings agency said the executive changes “have put at risk fiscal and growth outcomes”.

"The downgrade reflects our view that the divisions in the ANC-led government that have led to changes in the executive leadership, including the Finance Minister, have put policy continuity at risk," S&P said in a statement.

During the shuffle, Zuma replaced the highly respected Pravin Gordhan with Malusi Gigaba, who was previously Home Affairs Minister.

The negative outlook, meanwhile, reflected a view that political risks would remain elevated in 2017 and that policy shifts were likely.

The agency saw higher risks of Budgetary slippage, and upward pressure on South Africa's cost of capital, which would further dampen already-modest growth.

Also reassessed was South Africa's contingent liabilities, reflecting an increased risk that nonfinancial public enterprises, such as Eskom, would need further “extraordinary government support”.

S&P Global Ratings lowered the long-term South Africa national scale rating to 'zaAA-' from 'zaAAA'.