Singapore's founding prime minister Lee Kuan Yew is "critically ill" and his condition is worsening further while on life support in hospital, the government said Wednesday. The 91-year-old, widely credited with transforming Singapore from an economic backwater into one of Asia's wealthiest economies, has been receiving treatment for severe pneumonia in the intensive care unit at Singapore General Hospital since February 5. "Mr. Lee Kuan Yew remains critically ill in the ICU and has deteriorated further," said a statement from the office of his son, Prime Minister Lee Hsien Loong. - Iron-fisted rule - On Tuesday, the government said his condition had worsened due to an infection, for which he was given antibiotics, and doctors were closely monitoring his condition. The senior Lee has been breathing with the help of "mechanical ventilation," a form of life support, according to previous government statements. Lee modernised Singapore's economy but rights advocates have criticised the British-trained lawyer for his iron-fisted rule, which has seen political opponents jailed or driven to bankruptcy through costly libel suits. Singapore strictly controls freedom of speech and assembly and, while it has become more liberal in recent years, still uses corporal punishment for crimes considered relatively minor elsewhere, such as spraying graffiti. A longtime fitness buff, Lee has visibly slowed since his wife of 63 years, Kwa Geok Choo, died in 2010. In a book published in 2013, the Asian elder statesman said he felt weaker by the day and wanted a quick death. Prime Minister Lee posted the latest update on his father on his Facebook page and was immediately inundated with expressions of support, prayers and wishes for the patriarch's recovery. Many said they hoped he would live long enough to witness Singapore's 50th anniversary of independence on August 9, an event known as "SG50". It gained self-rule from colonial ruler Britain in 1959 and became a republic in 1965 after a brief and stormy union with Malaysia. "My prayer to Mr Lee Kuan Yew. Hang on. Please be around to celebrate SG50 with the nation," wrote reader Elena Wee Meng Gek. - Vigil at hospital - Netizen Sangeetha Prasad wrote: "I just don't want him to suffer so much! It is really so heart wrenching! If only love could heal!" Others were resigned that he may not recover. "No matter what the outcome is, most important is that Mr Lee Kuan Yew does not suffer. My prayers to him," wrote reader Jessie Seah. Crowds began to gather at the hospital following the latest bulletin, according to an AFP reporter on the scene. One of his grandsons was also seen entering and leaving the hospital. "It will be sad when he dies. He has his flaws but (he) has achieved a lot for this country," teaching assistant Imad Alatas, 33, said at the hospital. Civil servant Asyraf Jalil, 26, said: "He is a good man and I've always seen him as the father of modern Singapore." Lee served as prime minister from 1959 until he stepped down in 1990 in favour of his deputy Goh Chok Tong. Goh in turn handed the reins to Lee Hsien Loong in 2004. The People's Action Party (PAP), which was co-founded by the elder Lee, has won every election since 1959 and currently holds 80 of the 87 seats in parliament. Lee is still an MP for the port district of Tanjong Pagar, but retired from advisory roles in government in 2011. He had previously held the special cabinet positions of senior minister and later "minister mentor" after stepping down as premier. In a newspaper column in 2011, Lee's physician daughter Lee Wei Ling revealed that he had been battling a neurological disease that makes it difficult for him to walk. Lee's last high-profile public appearance was in November, when despite requiring assistance to walk and stand, he momentarily got to his feet to receive a standing ovation at the 60th anniversary of the founding of the PAP. Lee Hsien Loong, 63, was himself discharged from hospital on February 18 after undergoing surgery for prostate cancer. His doctor has said he should make a full recovery.