Prime Minister Julia Gillard is refusing to discuss accusations regarding her resignation from a prominent law firm in 1995, saying it wouldn't stop the "malicious and motivated" commentary.

News Limited has reported that Ms Gillard quit the firm as a direct result of a secret internal investigation into controversial work she had done for her then boyfriend, a union boss accused of corruption.

The new claims have been made by a former partner at the firm, Nick Styant-Browne.

Slater & Gordon says the internal legal review was a standard response to the allegations made and nothing was found to contradict Ms Gillard's statements.