President Robert Mugabe is insisting he remains Zimbabwe's only legitimate ruler, an intelligence source said. File picture: Themba Hadebe/AP

Johannesburg - Zimbabwe President Robert Mugabe and his wife Grace are "ready to die for what is correct" and have no intention of stepping down in order to legitimise this week's military coup, his nephew, Patrick Zhuwao, said on Saturday.

This as several thousand people gather in Zimbabwe's capital on Saturday to demand the departure of Mugabe, one of Africa's last remaining liberation leaders, after nearly four decades in power.

The dancing crowds in Harare were making it clear the country is impatient to move on without Mugabe, who took power 37 years ago amid an air of optimism but has been accused of squandering the once-prosperous country's potential.

The 93-year-old Mugabe, the world's oldest head of state, is said to be asking for more time amid negotiations with regional leaders that seek his exit with a veneer of dignity.

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Speaking to Reuters from a secret location in South Africa, Zhuwao said Mugabe had hardly slept since the military seized power on Wednesday but his health was otherwise "good". 

Reuters and AP