Mon-Thurs: Analysis of news and current affairs, presented by Sarah Montague. Fri: Analysis of news and current affairs, presented by Mark Mardell.

Mon-Thurs: Analysis of news and current affairs, presented by Sarah Montague. Fri: Analysis of news and current affairs, presented by Mark Mardell.

Mon-Thurs: Analysis of news and current affairs, presented by Sarah Montague. Fri: Analysis of news and current affairs, presented by Mark Mardell.

In an exclusive interview for Radio 4's World at One, Sir Paul McCartney tells Sarah Montague how his 'Meat Free Monday' campaign came about, shares his thoughts on young climate change activists, and his unreleased record of Christmas carols, made just for his family. He also talks about appearing at Glastonbury in 2020.

(Photo: Sir Paul McCartney, with presenter Sarah Montague

Mon-Thurs: Analysis of news and current affairs, presented by Sarah Montague. Fri: Analysis of news and current affairs, presented by Mark Mardell.

The Labour leader Jeremy Corbyn talks to Martha Kearney about the crisis in Yemen and his party's approach to Brexit.

(Photo: Jeremy Corbyn. Credit: BBC)

In a series of pieces, Manveen Rana has been investigating the relationship between political power in South Africa, a London-based PR firm, and one of the country's richest families.

As the President faces a vote of no confidence, what links Jacob Zuma, the Gupta Brothers and Bell Pottinger Public Relations? And, with anger at corruption spilling over from the streets to parliament, has Nelson Mandela's rainbow nation been put in jeopardy by a political campaign born in Britain?

(Photo: Protesters in South Africa. Credit: Getty Images)

Until recently, South Africa was hailed as one of the so-called BRICS - the developing economies, growing at such a rate of knots, they were soon to join the economic premier league. Not anymore.

Next week, President Jacob Zuma faces a vote of no confidence, fuelled by accusations of financial corruption on a gargantuan scale.

One of the principal businesses to have been roped into the scandals are the Gupta brothers, a family whose tentacles extend from media-ownership to railways, coalmines and armaments; the common thread being the ownership of formerly state-run companies.

The Guptas have been the subject of highly critical media coverage, as well as a report by the South African public protector's office into their links to government ministers, President Zuma himself, and members of his family. The Guptas strenuously deny any suggestion of corrupt behaviour. Indeed, not only have they submitted sworn affidavits to the contrary, but they say the media is in the hands of a 'white monopoly capital', which is hell-bent on tarnishing their name, along with a few old white families who ensure their business is stymied at every turn.

In the third of four special reports, Manveen Rana was granted a rare interview with Atul Gupta and discussed, frankly, their reputation.

(Photo: Protesters in South Africa. Credit: Getty Images)