The taxpayer-funded jet service should only be used when a commercial airline seat is not a viable option. Department of Finance rules on entitlements state: "When considering tasks for special purpose aircraft, the approving authorities will take into account: a) the availability of flights on major domestic airlines." High flyer: Joe Hockey's VIP flights cost $13,530. Credit:Nick Moir But in a two-month period between October 16 and December 12, 2013, eight ministers took 35 flights on busy intercity routes. The bill to taxpayers was $182,160. But that does not reflect the total cost. Once fuel, crew, catering and landing fees are considered, the 35 flights cost the public closer to $900,000, according to a formula established by the ABC Fact Check unit. The schedule of special purpose flights, tabled twice a year in Parliament, records 15 so-called "ghost flights" among the 35 flights where an RAAF Boeing 737 jet flew to or from Canberra without any passengers.

Ghost flights added $70,000 in additional costs. Treasurer Joe Hockey is the named minister on eight flights between Sydney and Canberra - one of Australia's busiest air routes, particularly when Parliament is sitting. They included three ghost flights costing $5940. In total, Mr Hockey's flights cost $13,530. Joining him on some of those were Sydney-based ministers Malcolm Turnbull and Arthur Sinodinos and Treasury boss Martin Parkinson. Mr Hockey's office declined to comment on why VIP flights were needed on the busy route.

On November 28, Health Minister Peter Dutton is listed as having put just one staff member, Tom Fleming, a senior health adviser, on a flight between Sydney and Canberra. His office explained that the special purpose flight was returning to Canberra after taking the minister between Hobart and Sydney and Mr Fleming stayed aboard. Defence Minister David Johnston and his assistant minister Stuart Robert were the most prolific users of special purpose aircraft on commercial routes, notching up 14 flights between them - largely between Canberra and major capitals including Melbourne, Perth, Adelaide and Brisbane. A spokeswoman for Mr Johnston, who has portfolio responsibility for the RAAF, said all flights in the register were within guidelines. She said flights taken by the minister between Perth and Canberra were necessary because there is generally just one direct commercial flight a day. The Opposition declined to comment on the government's use of VIP aircraft. In the frenetic last six weeks leading up to the election, Labor ministers took 42 flights on routes that are covered by Qantas and Virgin.

Loading It has been reported that former Prime Minister Kevin Rudd racked up bills of $100,000 a week in special purpose travel when he returned to the leadership in 2013. Follow us on Twitter