While a disciplinary process would follow the separate decision to suspend Mr Woolas from the Labour Party, Ms Harman said the fact he had made false statements about his opponent in May's general election would not change "and that is what we are taking action on".
She went on: "It is not part of Labour's politics for somebody to be telling lies to get themselves elected."
Mr Woolas was suspended after Friday's judgment of a specially convened election court - the first of its kind for 99 years.
The court heard he stirred up racial tensions in a desperate bid to retain his Oldham East and Saddleworth seat, which he eventually won by 103 votes ahead of Lib Dem Elwyn Watkins, who brought the challenge.
His campaign team was said to have set out to "make the white folk angry" by depicting an alleged campaign by Muslims to "take Phil out".
Mr Woolas announced after the verdict that he would seek judicial review of the decision.