Conservative commentator Gerard Henderson has been dropped as a panellist from ABC’s top-rating Sunday morning political program Insiders.

ABC sources confirmed a Guardian report claiming Henderson would make way for other conservative voices. The sources say this decision was made a few weeks ago and is unrelated to Henderson’s recent defence of a Catholic school accused of mishandling a “child grooming” case.

Gerard Henderson. Credit:Edwina Pickles

Henderson, the executive director of the Sydney Institute think tank, was not available for an interview but provided a copy of a letter he had submitted to The Australian newspaper.

On Monday, Australian columnist Chris Mitchell praised new Insiders host David Speers as “scrupulously fair and the best ­political interviewer in the post-Laurie Oakes era”, while reporting that Henderson’s future on the program was uncertain.