While questions are being raised around Mr Joyce’s travel expenses, the employment of Ms Campion and his relationship with a prominent New England businessman, Mr Turnbull said the real issue is the “terrible hurt and humiliation” the Deputy Prime Minister had inflicted on “his wife Natalie, and his daughters, and indeed his new partner”. 

“Barnaby made a shocking error of judgement in having an affair with a young women working in his office,” Mr Turnbull said.

“In doing so, he has set of a world off woe for those women and appalled all of us.

“Our hearts go out to them. It has been a dreadful thing for them to go through in the glare of publicity.”

In response to the scandal, Mr Turnbull announced changes to the “truly deficient” Ministerial Code of Conduct, to reflect modern workplace standards.

“Ministers, regardless of whether they are married or single, must not engage in sexual relations with their staff – doing so will constitute a breach of the standards,” he said.

However, the change would not be applied retrospectively, Mr Turnbull said as he struggled to explain how it would affect his beleaguered colleague.

“If [Barnaby Joyce] did what he did, you know, last year, ah, tomorrow, or today, ah, he would be in breach of the code, yes,” he said.

When asked whether Mr Joyce should resign, Mr Turnbull deflected the question and said “he has to consider his own position”.