Miss Allan, 40, who has already won out-of-court settlements of almost pounds 40,000 over similar allegations, was suing Channel 4 over a documentary first shown in April 1991. She has never sued over numerous similar articles published in South Africa.
The defence said the film, The Leader, His Driver and the Driver's Wife, first broadcast in April 1991, mentioned Miss Allan only briefly, did not suggest that she had had an affair with Eugene Terre- Blanche, the leader of the Afrikaner Resistance Movement (AWB), and, if it had, the allegation would have been justified.
Outside the court Miss Allan said she had been opposed by 'political forces,' adding: 'I think the British jury and British courts found it difficult to grasp the moral turpitude which exists in South Africa.'
She did not have pounds 300,000, and would have to raise it, but would not say how. She said she planned to continue libel actions against the Daily Mail and the Daily
The court heard evidence of incidents which, according to Channel 4, proved there was an affair, but which Miss Allan had dismissed as 'utter and complete inventions'. In May 1988, a former flatmate and a fellow journalist, Linda Shaw, said she saw Miss Allan and Terre-Blanche having sexual intercourse on a bedroom floor. She said Miss Allan told her Terre-Blanche was 'a great lay but a little heavy'.
A former senior official in the AWB, Cornelius 'Kays' Smit, described how the couple danced and goose-stepped at his home, and how he once found Mr Terre- Blanche drunk at Miss Allan's flat, wearing only green underpants with holes in.
A stolen notebook written by Miss Allan and detailing sexual encounters with Captain Ricardo, a married airline pilot, arrived anonymously at the offices of the defence's lawyers while Miss Allan was in the witness box. She claimed its contents were fantasies.
If the publications that settled out of court believe the verdict means Miss Allan made a material misrepresentation of fact to them which induced them to settle, they can apply to the court to have the settlement set aside.
Ivor Cole, legal director of Associated Newspapers, which owns the London Evening Standard, one of those settling out of court, said he was reviewing the situation.