The MP who disclosed his girlfriend on the register of interests as a potential conflict is "bewildered" by Julie Bishop's insistence on avoiding scrutiny of her boyfriend.

Key points: Reports highlight Julie Bishop has claimed tens of thousands in travel entitlements for David Panton

Reports highlight Julie Bishop has claimed tens of thousands in travel entitlements for David Panton Ms Bishop argues Mr Panton is entitled to travel because he is her "nominated person"

Ms Bishop argues Mr Panton is entitled to travel because he is her "nominated person" Labor says Ms Bishop is walking a "very fine line"

David Panton, reported variously as a pharmacist, winemaker and property developer, has accompanied the Foreign Minister at functions she attended in an official capacity, including on the floor of the United Nations.

Reports this week highlighted how Ms Bishop had claimed tens of thousands in travel entitlements for Mr Panton in the past three years.

Yet Ms Bishop argues Mr Panton is entitled to travel because he is her "nominated person".

She has told triple j she is "absolutely, 100 per cent compliant with the rules".

When asked whether her circumstances passed the "pub test", she was adamant she had done nothing wrong.

"These are the rules that apply to all members of parliament, and I comply with them," she said.

"That's the test that members have to meet in relation to the Register of Interests and appropriate declarations, and I've made them."

Tasmanian MP Andrew Wilkie declared in March 2017 that he had commenced a relationship with "a senior RACGP [Royal Australian College of General Practitioners] official".

He marked this under the section "where a conflict of interest with a member's public duties could foreseeably arise or be seen to arise".

He told the ABC that he made this declaration "out of concern that there could a perceived conflict of interest when it came to my approach to health policy".

"Ms Bishop may be in a similar position which would potentially be another reason for Mr Panton being included somewhere in her register," he said.

The Foreign Minister says she was mesmerised by the hairstyles of Kim Jong-un and Donald Trump. ( Reuters: Andrew Kelly )

Benefit is 'only available to spouses'

Mr Wilkie claims he is "bewildered" by the situation.

"On the one hand she doesn't seem to regard Mr Panton as her spouse because she doesn't include any of his details in her Register of Member's Interests," he said.

"But at the same time she is claiming Mr Panton is eligible to travel at public expense, which is a benefit normally for spouses."

His comments followed those of Labor MP Brendan O'Connor, who described Ms Bishop's justification as a "very fine line".

"I understand she's indicating that he's not her de facto partner or husband and therefore is seeking to distinguish whether in fact he needs to declare his interests," he said.

"I think there would be people who would reasonably argue that there needs to be more accountability in relation to that matter."

Liberal MP Sussan Ley — who experienced her own interests scandal — defended Ms Bishop's use of travel entitlements.

"Julie is completely within the rules," she said.

"I think there there is a lot of unnecessary speculation about her private life."

To declare … or not

According to the Register of Interests itself, its purpose "is to place on the public record Members' interests which may conflict, or may be seen to conflict, with their public duty".

A close reading of the rules governing the register requires MPs to disclose shares, gifts, directorships and other potential conflicts of interests for both them and their "spouses".

However "spouse" is not defined. A common general legal definition requires a legal marriage.

The entitlements scheme allows MPs to claim family travel for a spouse or "nominee".

Barnaby Joyce has not disclosed the interests of his new partner Vikki Campion. ( ABC News/ABC News: Jed Cooper )

Ms Bishop has argued Mr Panton is her nominee.

Other MPs have taken different approaches to declaring — or not declaring — details of their relationships.

Nationals MP Barnaby Joyce's form includes the interests of Natalie Joyce.

His form has them marked as "separated".

Mr Joyce has not disclosed the interests of his new partner Vikki Campion.

Queensland MP Bob Katter has not declared the interests of his spouse.

He stated on the register that "she does not provide me with this information — regards this as personal news".