Tanzania's President Benjamin Mkapa is not using his new presidential jet to attend a meeting in Ethiopia after criticism from the opposition.
The jet has been nicknamed the Flying Ikulu or Flying Statehouse
The controversial $40m US Gulfstream G550 jet arrived in Tanzania on Friday.
No explanation was given as the president left Dar es Salaam for Addis Ababa on an Ethiopian Airlines plane.
An oppposition leader described plans to take the plane to an African Commission meeting to discuss poverty as "really embarrassing".
The jet was expensive and the money could have been better spent on education and health, Professor Ibrahim Lipumba of the main opposition Civic United Front said in light of the proposed destination for its first flight.
"For President Mkapa to use that jet to go to Addis Ababa to the African Commission meeting... to tell Mr Blair, 'Please give us more money so that we can fight poverty in Tanzania,' it's a real shame," he told the BBC's Network Africa programme.
The government allocated less than a dollar for every Tanzanian facing hunger over 12 months, he said.
Earlier, Transport Minister Mark Mwandosya defended the purchase of the plane, saying the president could not hitch a lift from another president.
"What is the cost of the pride of the nation? The number does not mean anything as long as we buy the plane, maintain it and look after the welfare of our people," he said.
The jet, which flew intoTanzania last Friday to a big reception, replaces an aging Dutch Fokker 28, which presidents have been using for the past 25 years.
Susan Mashibe, the jet's new pilot and a maintenance contractor, says the 18-seat plane will save the government a lot of money because it can be easily maintained.
According to the BBC's Vicky Ntetema in Dar es Salaam, public opinion is divided over the jet, nicknamed the Flying Ikulu, meaning Flying Statehouse.
Some say as a matter of pride the country should have its own high-tech presidential jet.
But others feel it is a waste of money, arguing the president should travel by passenger plane.