Barnaby Joyce hatched a secret plan to get embattled Liberal MP Craig Kelly to defect to the National Party.

The former Nationals leader tried to save the staunch conservative as he faced being dumped by the Liberal Party in a bitter preselection battle.

"I certainly did reach out to Craig, to say anything else is not the truth," Mr Joyce told Network Ten on Tuesday.

"I always did say to him that the best option is to be preselected for the Liberal Party, quite obviously.

"But if he wasn't in the Liberal Party then the worst option, I think, for our parliament was to lose him."

Mr Kelly, who represents the Sydney seat of Hughes, admits it would have been an option of last resort.

"I don't know if an Akubra would fit me, and the RM Williams boots are not really my style," he told Network Ten.

The plan came to nothing, because Prime Minister Scott Morrison personally intervened to save Mr Kelly last week, keeping him in the Liberal Party tent.