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…