Mandela's wife at his bedside after cancelling London trip

Nelson Mandela's wife Graca Machel called off a trip to London this week to be with her ailing husband who was readmitted to a hospital with a lung infection today.

Nelson Mandela's wife Graca Machel called off a trip to London this week to be with her ailing husband who was readmitted to a hospital with a lung infection on Saturday.

"Mrs Graca Machel cancelled her appointment in London on Thursday," South African presidency spokesman Mac Maharaj told AFP.

"This morning when Madiba was hospitalised she accompanied him and she is with him at the hospital," he said, using Mandela's clan name.

Machel was scheduled to attend a summit on hunger in London hosted by British Prime Minister David Cameron which opened on Saturday.

South Africa's revered first black president and Nobel Peace Prize winner is in a "serious but stable" condition in a Pretoria hospital, his fourth hospital stay in seven months.