London — Britain is beginning to wobble on South Africa. A major trading partner of South Africa, Britain has been conspicuously out of step with its 48 Commonwealth partners in resisting further sanctions and in refusing to talk with the African National Congress (ANC), a banned organization that seeks to overthrow white-minority rule in South Africa.
But in a major policy switch, the No. 2 official at the British foreign office has invited acting ANC President Oliver Tambo to meet with him in London this week. Mr. Tambo is reported to be considering the invitation.
It will be the first official meeting between a representative of the government of Prime Minister Margaret Thatcher and the black nationalist organization -- and reflects an awareness in London of the rapidly shifting situation in South Africa.
Until now, Britain has steadfastly refused to meet with the ANC which it says uses violence.
There are growing indications, too, that an increasingly isolated Britain feels it necessary to make some further gesture on the issue of sanctions.
Mrs. Thatcher has repeatedly said she is philosophically opposed to sanctions.
But, say analysts, Thatcher is caught between her Commonweath and European partners -- who say she is not doing enough -- and about 80 right-wing Conservative Party Members of Parliament in a rebellious mood over possible further sanctions against South Africa.
Diplomats here say Thatcher will be obliged to make some minimal gestures toward firmer measures against South Africa, such as no new investment, that would get her off the hook at the European Community's ``sanctions'' summit scheduled at The Hague this Thursday.
To forestall any significant action until the summer recess of Parliament, when her angry Conservative MPs will be conveniently out of the way, Thatcher is thought to be contemplating sending Foreign Secretary Sir Geoffrey Howe to South Africa. The objective: to try to persuade South African President Pieter W. Botha to release prisoned ANC leader Nelson Mandela. But critics see it only as a measure to buy time.
Meanwhile, pressures are mounting on Britain to act more decisively to cut its links with South Africa.
Mr. Tambo, who serves as acting head of the ANC for the imprisoned Mr. Mandela, voiced his disapproval of British strategy on South Africa at a news conference here yesterday.
The lawyer said, Britain ``in its recalcitrance is not alone.'' This was an allusion to the reluctance of two other major powers, the United States and West Germany, to impose comprehensive sanctions.
Tambo expressed his suspicions that the report of the Commonwealth's Eminent Persons Group, which called for the release of political prisoners and wider sanctions, might be pigeonholed and be overtaken by a possible peace mission by Sir Geoffrey Howe.
``The history of the past 10 years of South African negotiations was dismal. We do not want a repetition of meaningless so-called negotiations. Pretoria must prove its bona fides.''