Former Abbott government minister Eric Abetz has suggested journalists interrupting politicians in interviews could be considered "offensive and insulting" amid a push to change controversial provisions of the Racial Discrimination Act.

During an interview with ABC Radio's Fran Kelly on Wednesday morning, the conservative Tasmanian senator asked to be given the opportunity to finish his answers before suggesting some might consider his being interrupted as "insulting" or "offensive".

Senator Abetz is backing Liberal backbencher Cory Bernardi as he prepares to present a private member's bill to amend ­the act. Senator Bernardi has the support of at least 20 senators including all but one of the Coalition's backbench in the upper house. The bill would re-write the law to drop "offend" or "insult" from the act, while leaving in "intimidate or "humiliate".

Changes were considered and then dropped by the Abbott government and the renewed push for change is being seen as a challenge to Prime Minister Malcolm Turnbull's authority.