She issued a statement through her solicitors which described as "untrue" claims made by David Horton-Fawkes, Earl Spencer's business manager, that she was using the divorce hearing to make malicious allegations and to make money.
Mr Horton-Fawkes made his statement outside the High Court in Cape Town on Thursday. He said Lady Spencer "has been persuaded or advised to use this public forum and the protection of open court to make malicious and untrue allegations against Charles [the earl] for financial gain".
But in her statement, the countess said: "I simply wish to state in response to what is said by - or perhaps through - Mr Horton-Fawkes that it is in material respects quite untrue.
"My husband chose to sue me in South Africa for divorce and for the custody of our four small children in South Africa, without warning, when we had been involved in negotiations through our English solicitors for many months, with a clear view to a divorce in England.
"My struggle before the Cape Town court is to have my future, and that of my children, determined by the law of the land where we were born and to which we shall return."
Earlier, one of the women with whom Lord Spencer is alleged to have had an affair leapt to the defence of the countess.
Sally Ann Lasson said of Mr Horton-Fawkes's attack: "Well, it's his [Lord Spencer's] little sidekick, in his anaemic lackey way, trying to justify the fact that this man who has over pounds 100m won't write a little, tiny cheque to his wife.
"And then blaming the wife for going to court to get publicity, which is preposterous."Reuse content