Campion confirmed she started working this week for the party's NSW state executive, after helping NSW One Nation leader and Cessnock candidate Mike Newman with a press conference in the Hunter electorate on Tuesday.
Campion said it was "publicly disclosed that I [am] married to Barnaby on my website and the public are aware of my affiliation with One Nation through many media reports."
"I've worked as a political contractor for around six years across a range of campaigns and candidates while writing regularly and running a farm," she said. "I report to the NSW state executive which is a separate entity to the federal One Nation, and I have previously worked for the state Nationals in similar arrangements."
Campion writes a weekly column for the Saturday Telegraph, with her latest published on 9 October. Asked whether she would disclose her work for the party in future columns, she said: "as an opinion writer, I don't think anyone who has read my column would be shocked that I would want to help One Nation."
After Guardian Australia put questions to the Daily Telegraph about the arrangement, the paper published an article on her new role. Campion told the Telegraph it was a "natural extension" of her career as a conservative commentator, and the paper stated she would continue writing her weekly Saturday column.
Campion later posted on social media that the party "is a phenomenon and unlike anything Australian politics has seen in a very long time."
Campion previously worked as a media adviser to Joyce when he was deputy prime minister; the pair married in 2023. In an appearance on the ABC's Australian Story in August, she said she felt "suicidal" during a press conference called by the then prime minister, Malcolm Turnbull, after the Daily Telegraph published a front-page photo of a pregnant Campion in February 2018, following Joyce's late 2017 announcement that he and his first wife had separated. The ABC later issued an apology after its news Instagram account published a clip from the episode discussing her experience of postpartum depression without disabling comments.