Embarrassed chiefs at Portugal's flagship airline have had to tell their Prime Minister they cannot fly him to Macau for an official visit next month. Air Portugal/Transportes Aereos Portugueses (TAP) has already committed all of its long-haul aircraft, leaving Prime Minister Antonio Guterres grounded. He is due to arrive in Macau on April 17 for a three-day visit before flying to the mainland to visit Chongqing, Shanghai and Beijing. Airline bosses initially considered using Cathay Pacific. However, the plan was dropped amid official concerns it would breach protocol for a Portuguese prime minister to fly to Macau under what could be considered a Chinese flag. A Macau Portuguese-language newspaper, Ponto Final, reported Air Madeira, the flag carrier of the Portuguese island autonomous region off North Africa, had come to the rescue with a replacement plane. Madeira has a long-haul Lockheed aircraft because there is a heavy demand for flights to the United States and Venezuela, which has a large Madeiran community. It is the same plane which flew former Portuguese president Mario Soares to Macau three years ago. TAP flies to Macau twice a week using Airbus planes. Last night a spokesman for TAP in Lisbon said: 'We have no comment to make on this news.' The director of the Macau delegation of TAP, Dr Alvaro Brasao Antunes, also remained tight-lipped.