South Africa's Deputy President Cyril Ramaphosa saw his chances of becoming the country's next leader increase on Thursday when a powerful union group backed him to succeed President Jacob Zuma as head of the ruling party.
Zuma is expected to stand down as African National Congress (ANC) president at a party conference in December next year, ahead of national elections in 2019 when his tenure as the country's president will end.
The debate over who should follow Zuma has heated up since the ANC suffered its worst local election results in August, exposing party divisions.
The ANC's dominance of South Africa since apartheid ended in 1994 means it is widely expected to win the 2019 election, making its next leader almost certain to become president.
No one has declared an ambition to run but informal positioning is well under way, with the ANC split between backers of Ramaphosa, a former anti-apartheid leader popular with investors, and those who feel he would be too pro-business.
The Congress of South African Trade Unions (Cosatu), a member of the ruling political alliance that claims to represent 1.8 million workers, told reporters it had "resolved to campaign" for Ramaphosa ahead of the party conference.
An articulate though often programmatic speaker, Ramaphosa is likely to face strong competition if he does compete, including from Zuma's ex-wife, Nkosazana Dlamini-Zuma, head of the African Union.
The National Union of Mineworkers, one of South Africa's biggest unions, backed Ramaphosa in September.