The Papua New Guinea Institute of National Affairs says the purchase of an executive jet to be used by Cabinet Ministers cannot be justified.
State-owned Air Niugini has confirmed to the Post Courier newspaper that it is buying a Falcon jet for use by the Government and resource companies.
The airline says the cost of the aircraft is less than the reported 40 million US dollars.
The Institute of National Affairs Executive Director, Paul Barker, says with the aircraft able to land in only four towns in PNG it is clearly intended for international use.
He says given a budget blowout and a projected big fall in tax receipts, the Government should be focussing its money on a fiscal stimulus package and the maintenance of basic infrastructure and services.
"Really, funds should be really tightly directed into the most productive activities for wider economic and social benefit. It is very hard to see the purchasing of an aircraft, that clearly isn't going to be around the country very much, and has to be purchased in foreign exchange, is really going to contribute very much in that regard."