African National Congress deputy president Cyril Ramaphosa.

Cape Town - South Africa should adjust labour laws so union members have to vote before striking, Deputy President Cyril Ramaphosa said on Thursday, suggesting the government may push ahead with reforms to curb damaging industrial action.

The longest and costliest strike in South Africa's history in the platinum sector earlier this year dragged the continent's most advanced economy into contraction and prompted Standard & Poor's to downgrade its sovereign credit rating.

The country's biggest union, the National Union of Metalworkers of South Africa (Numsa), stopped work on July 2 demanding higher wages, halting output at several car factories.

The present system allows unions whose negotiations with a company have not produced a deal to declare a wage dispute and call a strike without a ballot, giving 48 hours' notice.

Companies and politicians often argue that workers want to return to work but are intimidated into extending strikes by powerful union leaders.

“I would take a strike ballot as a normal type of process in the governance of strikes ... I am hugely in support of that,” said Ramaphosa, a trade unionist-turned-billionaire seen as the most likely successor to President Jacob Zuma.

“In view of the length of strikes that we've seen ... that is a matter that should be debated,” he told reporters in Cape Town, adding that any reforms should be handled sensitively.

Last year, in the run-up to 2014 elections, the ruling African National Congress party stalled on earlier promises to include strike ballots and picketing rules in amended labour laws currently before parliament.

Analysts said the ANC was holding back labour reforms due to pressure from its labour federation partner, Cosatu, with whom it forms a three-party governing alliance together with the South African Communist Party.

Any changes to South Africa's labour laws are unlikely to be implemented quickly as government, business and unions wrangle over terms in an effort to find a consensual agreement.

“Unionists will tell you that it should in no way begin to dilute or minimise the rights that we have enshrined in the constitution - the right to strike,” Ramaphosa said. - Reuters