Paris: Defence Industry Minister Christopher Pyne has flatly rejected the suggestion he is angling for the role of Defence Minister and issued a stern warning to his colleagues engaging in cabinet reshuffle speculation to focus on the jobs they have and not the ones they want.

Speaking to Fairfax Media at the Institute of Advanced Studies in National Defence in Paris, Mr Pyne fended off recent media speculation that he is undermining his senior colleague and current Defence Minister Marise Payne.

This week, one unnamed backbench Liberal MP told Fairfax Media Mr Pyne, who is more senior in cabinet than Ms Payne, was a "menace" and clearly positioning for the Defence Ministry.

"Whoever would be saying such a thing is a liar," Mr Pyne responded on Thursday, local time.