A special sitting of South Africa's parliament is due to vote on whether to begin impeachment proceedings against President Cyril Ramaphosa. The president is accused of covering up the theft of a large sum of foreign currency from his farm in 2020, some of which had been hidden in a sofa. The debate will focus on an independent report, which concluded he may have violated the constitution. Ramaphosa, who is up for re-election as ANC leader, denies any wrongdoing. The African National Congress has told its MPs to block a possible impeachment - although some could break ranks and side with opposition parties to vote for proceedings to get under way. But some last-minute legal questions could halt the sitting altogether. If Ramaphosa survives, he is thought likely to win re-election at his party's conference, which starts on Friday. He will then be in pole position to become the ANC's presidential candidate at the next election in 2024. The sitting to discuss the report, which was commissioned from a panel of legal experts by the speaker, began just after 12:00 GMT (14:00 local time). It opened with a discussion over whether MPs should be allowed to vote in secret — something which the speaker had rejected. After the debate closes, names of individual MPs will be called out to register their verbal vote. Ramaphosa needs a simple majority in the 400-member parliament to quash an impeachment. The 70-year-old leader has denied any wrongdoing calling the report, which he has challenged in the Constitutional Court, "flawed". Ramaphosa became president in 2018 pledging to tackle corruption. He replaced Jacob Zuma, whose time in office had been weighed down by many such allegations. This scandal erupted in June, when a former South African spy boss, Zuma-ally Arthur Fraser, filed a complaint with police accusing the president of hiding a theft of $4m (£3.25m) in cash from his Phala Phala game farm in 2020. Ramaphosa admitted that some money, which had been hidden in a sofa, had been stolen, but said it was $580,000 not $4m. The president said the $580,000 had come from the sale of buffalo, but the panel, headed by a former chief justice, said it had "substantial doubt" about whether a sale took place. South Africa has strict rules on holding foreign currency, which say that it must be deposited with an authorized dealer such as a bank with 30 days. It appears as though the president may have broken those rules, according to the panel's report. Furthermore, if the money was from selling buffalo as he said, this money should have been declared, rather than kept in cash. In his submission to the Constitutional Court, Ramaphosa wants the country's top judges to rule that the findings of the panel are unlawful and set aside. The president argues that the panel went beyond its scope when looking at whether he had a case to answer related to the robbery at the farm. He is also asking the court to declare that any steps taken by parliament on the back of the release of the report to be declared unlawful and invalid. — BBC