Barnaby Joyce's deputy has finally broken her silence on the scandal that has threatened her boss's leadership, describing his extramarital affair with a staffer as "very human", but also conceding many women feel "unease" about his actions.

Bridget McKenzie insisted Mr Joyce's job is not under threat, giving a "rolled gold guarantee" the party room will not dump him.

Senator McKenzie was labelled "The Phantom" by some in the Nationals for waiting more than a week to make a public statement about her leader's affair with media adviser Vikki Campion, a revelation that has battered the party.

National MPs and staffers had expressed concern that she was conspicuously absent from the public defence of Mr Joyce - not issuing a single public statement or consenting to a single media interview on the affair for eight days.