The Government will have to buy a second-hand aircraft if it wants to replace its Gulfstream IV jet before Ireland's presidency of the EU early next year.
Under EU rules, a tender for a replacement would have to be published for 52 days in the EU's official journal. These would take another two months to examine.
"If the Government wants a new aircraft quickly, it will have to buy it second-hand. That kind of time-lag is normal for all military equipment," said one source.
