DA leader Helen Zille has denied claims that she tried to recruit Congress of SA Trade Unions general secretary Zwelinzima Vavi to her party.
"Zwelinzima certainly has a lively imagination. Next he'll probably say I asked him to marry me," she said in a statement on Sunday.
"In all the many chats we have had over the years... I have never tried to recruit him to the [Democratic Alliance]. Maybe he wishes I had."
She said it was absurd, given their diverse approaches to growing the economy and creating jobs.
"If people disagree on their approach to South Africa's greatest challenge, it is impossible to absorb them into the same political party."
Vavi told the Sunday Times that Zille had "bugged" him to join her party at a football match.
He claimed Zille was preoccupied with recruiting him.
"She is very, very power-hungry because she has this mistaken view... that I can be recruited to the opposition ranks," he told the newspaper.
"She tried to recruit me, in person, to join the DA in the run-up to the local elections."
Vavi said he and the DA were like "water and paraffin" and he believed that Zille would take him on "at a personal level" because he had refused her advances.
Zille recalled an interaction between her and Vavi at the funeral of KwaZulu-Natal Judge President Herbert Msimang.
"Zwelinzima arrived late. There was only one vacant chair left -- next to me," she said.
"Because he wanted to sit in the front row, he had to take it... he did not have a hymn sheet, so I shared mine with him. I joked: 'This is probably the only time you and I will be singing off the same hymn sheet.' He had a good laugh. So did I."
Journalist and author Gus Silber commented on the social networking site Twitter: "If Helen Zille & Zwelinzima Vavi did join forces, they would have a cool Brangelina name. Either ZwelinZille or HelenZima."
Mail&Guardian Online editor Chris Roper responded: "... actually, if capitalism and communism get into bed, the unfortunate progeny is more screwed workers. Worst of both worlds."