“The presidency is currently experiencing serious budgetary constraints and unfortunately the budget that was allocated to you for travel and subsistence has been exhausted,” The Times quoted a letter as saying.

“We are therefore not in the position to fund any further flights until March 31, 2012. This benefit will resume with effect April 1, 2012.”

The leaders affected include 93-year-old Mandela who is currently in his home village of Qunu, his predecessor FW de Klerk and successor Thabo Mbeki who regularly mediates in African conflicts, the newspaper said.

But the presidency denied that the retired leaders had been affected and said it only applied to support staff.

“The presidency wishes to put it on record that the cost-cutting measures introduced do not affect former presidents and deputy presidents,” said a statement.

“These measures only apply to the support staff travelling with the principals.”

The offices of both Mbeki and De Klerk confirmed receiving letters notifying them of the temporary cancellation of their benefits, but refused to say how they would be affected, the newspaper said.

Presidency spokeswoman Zanele Mngadi told The Times that the current economic climate had forced the cuts and that staff have been told to rein in spending.

“The presidency is also exploring economy class travel for senior managers up to chief director level as part of the cost-saving measures,” she told the newspaper.

“All units within the presidency have been informed about cost-cutting measures and they have all accepted what is now called inside the Union Buildings the ‘financial diet’.”

After polygamous President Jacob Zuma took office, the spousal budget for his wives and children in the presidency nearly doubled to 15.5 million rands ($1.8 million, 1.4 million euros) up from eight million allocated to Mbeki.

The unit was a “very tiny component” of the office and will also be part of the trimmed spending, The Times reported Mngadi as saying.