US Edition President Jacob Zuma said in a bleak statement issued late last night that he had visited his predecessor in hospital and spoken to Mr Mandela’s team of doctors who he said were still doing their best to aid his recovery.
Although Mr Mandela appeared to rally over several days last week, he said that his condition has taken a turn for the worse since Saturday evening.
“The condition of former president Nelson Mandela, who is still in hospital in Pretoria, has become critical,” he said.
“The doctors are doing everything possible to get his condition to improve and are ensuring that Madiba is well-looked after and is comfortable. He is in good hands.” Mr Mandela is understood to have become increasingly weak and unresponsive and his family have been told to prepare for the worst.
The 94-year-old’s wife Graca Machel has kept a constant vigil at her husband’s bedside, sleeping frequently in a nearby room at Pretoria’s Heart Hospital.
Yesterday, she was joined by other members of Mr Mandela’s large family including his former wife Winnie, his daughter Makaziwe and granddaughter Ndileka.
Outside the hospital, a bank of flowers, cards and ballons wishing the former president well have built up.
Addressing the country’s first black president as “Tata", or “Father", one read: “You are stronger than anything. I am what I am today because of you.
From Karabo Chilwane and Magret Moila in Limpopo.”
Mr Zuma added in his statement that there was “no truth” in an earlier report that Mr Mandela, who is due to turn 95 in a matter of weeks, had suffered a heart attack when he was first admitted to hospital in the early hours of Saturday June 8.
It emerged over the weekend that a military ambulance transporting the Nobel laureate broke down on the motorway between Johannesburg and Pretoria, leaving him and his sizeable medical team waiting 40 minutes for a replacement in the winter night.
Mr Zuma said that “all care” had been taken to ensure his medical condition was “not compromised".
“There were seven doctors in the convoy who were in full control of the situation throughout the period. He had expert medical care. The fully equipped military Intensive Care Unit ambulance had a full complement of specialist medical staff including intensive care specialists and ICU nurses,” he said.
Nelson Mandela is almost universally adored by South Africans of all ages and races for leading the country out of apartheid and bringing the warring factions together ahead of the country’s first democratic elections in 1994.
Last night the news of his deteriorating health was met with deep sadness coupled with a sense of resignation that has grown with each of Mr Mandela’s three hospital admissions this year.
“South Africa has a heavy heart tonight,” wrote one of his countrymen on Twitter.
“Going to sleep with a heavy heart. Feeling so emotional about Mandela.
Didn’t expect to feel quite so broken,” another wrote.
Ranjeni Munusamy, a newspaper editor, added: “I finally know what to pray for: that he is not in pain and can feel our love. That’s all we can ask for now.”
Barack Obama, the US President, is due to arrive in South Africa with his family on Friday night for his first major visit to the continent since taking office.
The possibility of a meeting between the first black presidents of both South Africa and the United States has been eagerly awaited for years, but the White House said at the weekend that Mr Obama would defer to Nelson Mandela’s family on whether he would visit him.
“Ultimately, we want whatever is in the best interests of his health and the peace of mind of the Mandela family,” said Ben Rhodes, a deputy US national security advisor. “We will be in touch with them. If he has an opportunity to see the family in some capacity, that’s certainly something that we may do.”