Nelson Mandela, the imprisoned leader of the banned African National Congress, has been involved in "serious dialogue" with senior members of the government for almost three years.

The discussions, which date back to 1986, involved more than a dozen lengthy meetings with a "team of four" top government representatives led by Minister of Justice Kobie Coetsee.

There were also a number of other individual discussions with key figures from the government camp, I have been told by well-informed diplomatic sources.

It is reliably understood that the government's four-man "team" tried in vain for 18 months to persuade Mandela that he, and the ANC, should abandon some of the cornerstones of their strategy. This was presented as a precondition for possible future negotiations with the ANC.

In several separate meetings the "team" sought to persuade Mandela to agree that the ANC should abandon the following strategies:

• A one-man-one-vote unitary constitution
• Armed struggle
• Sanctions and disinvestment
• International isolation of Pretoria
• Mass mobilisation campaigns.

It took a number of lengthy discussions before the government "team had reluctantly to accept that Mandela would under no circumstances abandon these views.

It is understood that in order to pre- vent the talks from ending in dead-lock, or breaking down altogether discussions then began on the issue of releasing Mandela's jailed ANC colleagues. This led to the release of Govan Mbeki at the end of 1987 an later, some PAC members.

However, because of the controversial surrounding Mbeki's release (involving a major press conference and excited crowds), the government felt forced to restrict him in order to avoid further international embarrassment.

This somehow soured subsequent, tough discussions between the government "team" and Mandela, with him pushing for the release of others especially the 75-year-old Walter Sisulu.

The government "team" tried to establish ground rules with Mandela about how the Sisulu release should be handled, and wanted guarantees about 'behaviour” as well as an undertaking that there would be no rallies or press conferences. It is known precisely what transpired, but it is almost certain that Mandela was not prepared to provide the government with such guarantees.

Earlier this year the government apparently agreed in discussions with Mandela to release Sisulu by May this year. The matter of his own release was also bound to have been discussed.

Significantly, this was not long before the De Klerk visit to Europe, and probably formed the basis of subsequent leaks from the Thatcher camp that Sisulu was to be released just before or after the September 6 election.

However, this time the State Security Council -- fearing a repeat of the Mbeki release saga -- intervened at the last minute and prevented the release.

It will now probably take place, along with those of some other ANC leaders, only in the aftermath of the elections. This unexpected last-minute change in government plans on Sisulu apparently led to further tough talks between Mandela and the government 'team" about what the latter really had in mind on possible negotiations with the ANC.

These apparently paved the way for the subsequent Botha/Mandela meeting, which took place at the insistence of jailed ANC veteran. He had requested it from the outset of the talks.

From the government's handling of the affair, it is obvious that it has no clear-cut strategy yet on how to deal with Mandela and the ANC.

This strengthens security establishment fears -- stated in private -- that Mandela has taken the initiative, and has in a sense gained the upper hand in the three-year "dialogue".

It is believed that Mandela presented Botha with a 13-page document setting out the reasons why be and the ANC were rejecting the government demand that they should abandon some of their key strategies as a precursor to negotiations.

This failure of the government to shift Mandela's position has apparently led to tension and disagreements between some government figures and senior security officials on the National Security Council.

Security elements are apparently seriously concerned about the course the discussions with Mandela have taken, and in particular his visit to Tuynhuys. They believe it is Mandela, and not the government, who has gained from the encounter -- without making any basic concessions.

The alarm has been compounded by the fact that in his carefully-worded, brief statement, Mandela studiously avoided rejecting the "armed struggle", and insisted that real negotiations could only take place with the ANC itself -- and not with him individually in prison.

It reaffirmed Mandela's standpoint that he is only involved in a "dialogue" with the government in preparation for possible eventual negotiations with the ANC.

The recent statement by National Party leader FW de Klerk claiming that the "ball was in the ANC's court” -- as they had to commit themselves to a peaceful solution as Mandela had done -- was thus obviously wrong and misleading, I am told.

The facts about the Mandela-government discussions over the past three years clearly contradict the recent statement.

The De Klerk speech is seen as an effort to cover up confusion and disagreements in government circles about the Botha/Mandela encounter and other talks. It is, in addition, an other transparent attempt to drive a wedge between Mandela and the ANC --