Politicians have begun combing through their old flight records for any missing declarations, with at least one Liberal MP adding several previously undisclosed flights.

Liberal Jenny Ware, who was elected to the seat of Hughes at the last election, made several alterations on Thursday, adding business class upgrades she received on domestic and international flights to Sydney.

Ms Ware declared two upgrades from Canberra and Brisbane, in December 2022 and March this year, and an upgrade to business class on a flight from Denpasar, Indonesia, to Sydney in January of last year.

Her declarations noted the flight upgrades were offered, not requested.

Shadow Transport Minister Bridget McKenzie has also announced she will review her own travel records after it was put to her that she had not declared all upgrades she may have received.

Senator McKenzie has written to Qantas, Virgin and the administrators for Regional Express asking for records of any upgrades she may have received.

"I have been in parliament since 2011, and I want to understand the full comprehensive list, if there are inconsistencies with my public declarations I will absolutely make those changes," Senator McKenzie told Sky News.

Greens leader Adam Bandt's unspecified declaration of "occasional" flight upgrades has also been noted.

On Thursday morning, Opposition Leader Peter Dutton said there was a difference between people making mistakes on their registers of interests and intentional evasion.

"People declare flights or they declare pecuniary interests, and sometimes they get it wrong or they put it in late or whatever else, that's the human reality of it," he told Sydney radio station 2GB.

Mr Dutton said questions around other MP flight declarations was the federal government "throwing mud" to distract from its troubles.

He argued the difference in the case of the prime minister was that he purportedly solicited a benefit from Qantas.

On Thursday morning the prime minister's office clarified that Prime Minister Anthony Albanese never contacted anyone at Qantas in any manner to request a flight upgrade.

Earlier this week he dismissed the claim as an attempt by columnist and former Liberal staffer Joe Aston "to sell a book".

Senior Liberal James Paterson says he would support a broad inquiry into all politician travel and any perks they may have received.

All federal members of parliament are offered membership to the exclusive Qantas Chairman's Lounge program, and nearly all accept it.

Qantas has exclusive lounges in almost all its capital city airports, which are hidden behind a door marked "private" located near the Qantas Club and business class lounges.

Members are provided additional perks including priority booking and a customer service hotline for rapid support.

MPs are also offered free upgrades to business class or first class when available — though upgrades on international flights are generally rarer because those seats are typically already booked out by paying customers.

The perks are generally similar to those offered to "platinum one" frequent flyers, with the exception of the exclusive lounge, a status symbol for Australia's elite.