(Adds detail, background, paragraphs 6-7,10-14) By Shapi Shacinda LUSAKA, Aug 18 (Reuters) - Zambian President Levy Mwanawasa's health suddenly deteriorated on Sunday night and he required medical intervention, his vice president said in a statement on Monday. "Doctor Mwanawasa had been making steady progress until last night when his condition suddenly changed and required intervention," said Vice President Rupiah Banda. He did not say what sort of treatment Mwanawasa had received. Mwanawasa suffered a second stroke during an African Union summit in Egypt in June and was flown to France where he has remained in hospital. The Zambian health minister said earlier this month he was in a 'stable but heavily sedated' condition. Speculation that Mwanawasa, 59, may be unable to return to work has prompted demands that doctors examine him and decide whether he is fit to remain president. If parliament decides he is incapacitated, Mwanawasa could be forced to step down. Banda would take over as acting president and elections would be called. ECONOMIC SUCCESS The Zambian leader is a favourite of the International Monetary Fund and other Western donors, who extended billions of dollars in debt relief after he cracked down on government spending and launched the biggest anti-corruption drive since Zambia won independence from Britain in 1964. The Percy military hospital just outside Paris, where Mwanawasa was being treated, declined to comment and would not confirm that he was still there. "The team of doctors have reported that the intervention was successful but decribed the condtion of His Excellency the president as serious," Banda said in the statement. "The nation will be informed in due course on future developments" on Mwanawasa's condition. His policies have helped usher in strong economic growth, which averaged 5 percent over the last six years, while inflation declined to single digits in April 2006, for the first time in over three decades. Despite the debt relief package and major investments from China and India, Mwanawasa has battled a growing public perception that his strong fiscal record had done little to benefit most of the 11.5 million people in the copper-rich nation. Mwanawasa became vice president in 1991 after Frederick Chiluba ousted founding President Kenneth Kaunda in landmark multiparty elections. Soon after winning the presidency in late 2001, he stunned observers by turning on Chiluba. Mwanawasa narrowly defeated opposition leader Michael Sata in a presidential election in 2006. Sata accused Mwanawasa of selling out Zambia to Chinese and Indian companies. (Additional reporting by Estelle Shirbon in Paris; writing by Michael Georgy; editing by Tim Pearce)
