THE challenge facing South Africa's ruling African National Congress is coming more sharply into focus as President Nelson Mandela starts his gradual voluntary descent from the pinnacle of political life.

His personal popularity is probably higher than ever. The ANC, however, has shed the mystique of a resistance movement and is increasingly seen as a fallible political organisation. Since Mr Mandela was inaugurated as South Africa's first democratically elected President on May 10th, 1994, he has won the support of large segments of the white minority without sacrificing his status as a political messiah in the black community.

South Africans who are critical of the ANC are apt to preface their criticisms with complimentary remarks about Mr Mandela, particularly on his commitment to reconciliation and nation building. As a recent national opinion survey puts it: "There is massive satisfaction with Mandela across all races but ever diminishing levels of satisfaction the further down the political system one goes ... Massive majorities say they are dissatisfied or very dissatisfied with the government record on every single issue."

As Mr Mandela eases himself out of key positions - he will relinquish his leadership of the ANC at the end of the year before stepping down as President in 1999 - the ANC may find the existing difficulties of governance greatly magnified.

The problems facing the ANC led government of national unity can be illustrated by taking a look at the events which set the scene for the President's opening of parliament last week, an event which was marked by a new constitution drafted by democratically elected parliamentary representatives.

Only a few days before Mandela opened parliament, a Supreme Court judge was robbed of his car at gunpoint in a leafy Johannesburg suburb. The "hijacking" - as these robberies are known in South Africa - came after the President of the Constitutional Court, Mr Arthur Chaskalson, was confronted by bandits and robbed in his home. Crime, as these episodes show, remains a major problem and destroyer of public confidence in the future of the new South Africa.

Black newspaper columnist Jon Qwelane encapsulates the situation: "People . . . are scared because the huge crime wave has virtually made them prisoners in their own homes."

On the day before Mr Mandela's address, townships occupied by coloured people around Johannesburg were in turmoil as militants took to the streets to enforce a call by a civic association for a stay away or strike. The protest was initiated against higher rentals and service charges than those of surrounding black townships and the serving of eviction notices on residents in arrears with their payments.

Before the day was out, four people were killed and more than 200 injured. White and black policemen alike were stoned, petrolbombed and fired at by coloured demonstrators. The authorities who were castigated were sub structures of the ANC controlled Greater Johannesburg Metropolitan Council. A key grievance of the coloured community was that they were being threatened with eviction while residents in neighbouring black townships continued to run up huge arrears with impunity.

"Why are they not acting against people who, like us, cannot afford to pay in places like Soweto?" asked Amy Williams of the local civic association.

THE grievances have been referred to an investigation task committee headed by a member of the ANC controlled provincial government. But the underlying discontent in coloured townships remains. So, too, does the ANC's inability to persuade or cajole black township residents to pay service charges.

The multi million rand, taxpayer funded Mashakane campaign to induce them to pay has made little or no impact. The resentment in coloured townships is reflected in a slogan popularised by community leader Basil Douglas: "Under the white regime we were not white enough. Under the black government we are not black enough."

In Sandlon, an affluent, mainly white residential area, protest action of another sort has been gathering momentum for months. Residents, believing that their rates have been raised and their property values increased excessively, have embarked on a rates boycott. The target of their anger is the new ANC controlled local authority, which they accuse of profligacy and acting without proper consultation.

For the present, however, Mr Mandela and the man poised to succeed him, Deputy President Mr Thabo Mbeki, are concentrating on an overall strategic objective: a macroeconomic plan known as Growth, Employment And Redistribution or GEAR, which aims at raising the annual economic growth rate to 6 per cent by the turn of the century and generating at least 400,000 jobs a year by the same target date.

Aside from pressing ahead with plans to privatise or find "equity partners" for key state controlled industries, GEAR involves reducing the budget deficit to 3 per cent of GDP by 2000, a process which will require sharp cuts in government spending and which consequently entails the risk of accentuating disillusionment in the poorer strata of the population, particularly in the black community.

The danger for the ANC is that two events will converge as 2000 approaches: the departure of Mr Mandela who, more than any single person, has held the disparate elements of the multifarious ANC together, and growing dissatisfaction in the ANC's heartland constituency in the black community over slow or, in some cases, even non delivery of promises of a better life.

It is in that context that Mr Mandela's overtures to the Pan Africanist Congress and the Democratic Party to join the Government of National Unity must be seen. His attempt to offer sweeteners to the Inkatha Freedom Party - which is already a partner in the coalition government - falls into the same mould. On the last note, Mr Mandela's recent appointment of the Inkatha leader as Acting President during his absence in Switzerland comes to mind. Anticipating a fall in support by the 1999 general election, Mr Mandela, still a shrewd political tactician, has sought either to co opt rival parties or, in the case of Mr F.W. de Klerk's National Party, to isolate them.

Interesting times lie ahead as Mr Mbeki prepares to take over a difficult situation without the benefit of enormous goodwill which accompanied Mr Mandela's inauguration.