Panamanians are set to vote on Sunday (October 22) on a multibillion dollar plan to upgrade the Panama Canal. If Panamanians approve the plan to widen and deepen the waterway at a referendum on Sunday, the canal will receive the largest renovation it has ever gotten in its 92-year history. Opinion polls show around two-thirds of people approve the government's proposal for a $5.25-billion overhaul to allow increasingly large tankers to pass between the Atlantic and Pacific oceans. President Martin Torrijos has billed the referendum as Panama's most important vote since it became independent from Colombia in 1903 but opponents warn it could bankrupt the small nation if costs spiral. The Panama Canal Authority, or ACP, which runs the waterway, warns the route will become log-jammed in seven years if nothing is done, meaning business will be lost to competitors like the U.S. intermodal system of ports and cross-country rail links. The canal's outdated lock system is too small for many modern tankers. The proposal would provide new sets of wider locks and deeper and bigger access channels, double capacity and let ships with 12,000 containers pass through, up from a present limit of around 4,000 containers. Opinion polls show around two-thirds of people approve the government's proposal which would allow increasingly large tankers to pass between the Atlantic and Pacific oceans. Supporters of the expansion, planned to begin in 2008, hope it will bring a jobs bonanza for Panama's 3 million people. "The efficiency of the Panama canal will only be optimized by the expansion. We will be looking to the future and not the past. We avidly believe that Panama will be taking a step forward if the referendum is approved on Sunday," said Ernesto Fernandez, who is the Manager for the Barwil Agency's operations on the canal. Opened in 1914 at a cost of $375 million and 25,000 lives, the canal ranks alongside France's Eiffel Tower, the Golden Gate Bridge in San Francisco and the English Channel Tunnel as one of the world's most stunning engineering feats. Dynamited and dug out by thousands of mainly Caribbean labourers who braved deadly malaria and yellow fever, the canal saves ships a long haul around South America's treacherous Cape Horn and carries around 4 percent of world trade. Ships making the passage, mainly from the United States, Japan, China and Chile, also face longer waits these days to make the 50-mile (80-km) inter-oceanic trip as global shipping grows, partly due to the Asian economic boom. France's Ferdinand de Lesseps, builder of the Suez Canal, started the Panama Canal in 1880 but abandoned it nine years later when the project went bankrupt. The U.S. government bought the canal in 1904 and 10 years later opened the waterway, running it for most of last century. In treaties signed in 1977 by then U.S. President Jimmy Carter and Panama's populist dictator, General Omar Torrijos, agreed to hand over the canal to Panama in 1999.