Senate Minority Leader Robert J. Dole (R-Kan.), who will formally announce his presidential bid on Monday, is the target of a negative television ad debuting Sunday in Iowa that accuses him of being indifferent to the suffering of blacks in South Africa and states that he "just turns his back on apartheid."

The 30-second spot is sponsored by TransAfrica, a group that successfully lobbied Congress last year for sanctions against South Africa. Dole first supported a form of sanctions legislation, then opposed such legislation in a losing fight to sustain President Reagan's veto.

Dole, in an angry rebuttal, attacked the ads, saying, "These phony attempts to distort {my} record aren't going to fool anyone." And he attacked TransAfrica's Randall Robinson as someone "posturing as a civil rights leader" who "uses tactics that every responsible civil rights leader would reject."

The ad shows recent file footage of mayhem in South Africa as a voice-over charges, "While thousands of blacks are brutally jailed, Bob Dole just votes to look the other way." The screen fills with a rear view of a white man in a suit, an image also used to illustrate Dole "turning his back."

"We don't want a president who will do business with racists in South Africa," the voice-over continues as a "Whites Only" sign flashes. Then the camera lingers on a closeup of Dole. "So next time Bob Dole visits your state, make him face the consequences of opposing sanctions against South Africa."

The ad cost about $1,500 to produce and is expected to run about 100 times from Sunday through Tuesday in the four biggest media markets in Iowa, a key state in the 1988 campaign that is part of Dole's announcement tour next week.

Dole, in his statement, said he is "proud of my civil rights record" and says it reflects "strong opposition to apartheid." The senator outlined his efforts to get one version of sanctions through the Senate and what he called his efforts to "convince the president of the need to go along" with Congress on tough sanctions. He said he agreed to lead the effort to sustain Reagan's veto of a tougher sanctions bill because "we send a much stronger message to South Africa when we speak together, in one voice, than when we turn apartheid into a partisan, domestic issue."

Advertising executive Bill Zimmerman of Santa Monica, whose agency made the spot, said about $6,000 has been budgeted for air time. Robinson said TransAfrica plans to spend $100,000 or more to reach every primary and caucus state.

Dole attacked the timing of the ad and its ties to the presidential campaign. "Randall Robinson spewed out this venom once before," he said, "but his effort fell flat. Now he thinks he'll get a bigger audience, and maybe raise some money, by trying to exploit my announcement."

"The evidence supports the conclusion that Bob Dole has distinguished himself from the field," said Robinson in explaining why he singled Dole out rather than Vice President Bush, for example, whose administration fought sanctions vigorously. "Not only in his opposition to sanctions, but also in his sort of treacherous reaching of that conclusion after first supporting sanctions in August {of 1986}."

Robinson asserted that all the Democratic presidential candidates support sanctions against South Africa, but that former Delaware governor Pierre S. (Pete) du Pont IV is alone among Republicans in doing so.

"{Rep.} Jack Kemp {R-N.Y.} opposed sanctions, but he didn't flip-flop like Dole," Robinson added. "Bush has to be challenged to clarify his view. I haven't seen {former secretary of state Alexander M.} Haig's view, except that when he was in the administration, he was very pro-Pretoria. I don't know that {Christian broadcaster Marion G.} Pat Robertson has made any thoughtful statement at all."