South Africa’s main coalition partners are at loggerheads just weeks after agreeing to share power, as President Cyril Ramaphosa accuses Democratic Alliance (DA) leader John Steenhuisen of trying to create a “parallel government” in breach of the constitution.

He is said to have made the explosive allegation in a letter to Mr Steenhuisen on 25 June, which has been seen by local media.

Markets have slumped with the news of the deepening rift, at a time when Mr Ramaphosa’s African National Congress (ANC) and the DA are supposed to be divvying up cabinet posts and settling into office.

When the ANC failed to win an outright majority in last month’s election, the main opposition DA agreed to form a government of national unity that would keep President Ramaphosa in power – in exchange for DA politicians getting cabinet positions.

The ANC subsequently also signed a coalition deal with eight smaller parties, with Mr Ramaphosa under pressure to accommodate at least some of them in his cabinet as well.

Mr Ramaphosa penned his furious letter after giving the DA a final offer of six cabinet posts, according to local media reports.

The DA then demanded two further posts, reports the News24 website, which angered the ANC’s top brass.

Mr Ramaphosa’s letter accused the DA leader of “moving the goalposts” during the negotiation process.