Supporters of minimum wage say it will reduce inequality and stimulate economic growth

President Cyril Ramaphosa

More than 2,000 South African union members marched in Johannesburg in a nationwide protest against a proposed national minimum wage, presenting a test for new President Cyril Ramaphosa, who champions the policy.

The $1.6 (Sh160) an hour minimum wage, which Ramaphosa sees as an important step to tackle labour instability and wage inequality, was approved by the cabinet in November and is meant to be introduced on May 1. But dissatisfaction over the minimum wage bill could delay implementation.

Ramaphosa, who replaced Jacob Zuma as president in February, has staked his reputation on revising a stuttering economy and rooting out corruption associated with Zuma's nine scandal-plagued years in power.

The protests are the second major public show of discontent in South Africa in a week. Ramaphosa last week cut short a visit to a Commonwealth summit in Britain a day earlier to travel to the North West province where crowds have been protesting against poor public services.

The workers were marching several kilometres to the labour ministry offices in the commercial hub Johannesburg, holding aloft placards, one of which read: 'To hell with R20 per hour'.

"A minimum wage of 20 rand an hour is a spit in the face of the working class. Ramaphosa has sold out workers," said Moses Modisane, a shop steward for the metal workers union NUMSA, who works at an Anglo American mine near the city.

Supporters of the minimum wage say it will reduce inequality and stimulate economic growth, as workers can spend more.

But critics say it could lead to increased unemployment, already at record highs, with some employers unable to afford higher wage bills.