Chile is preparing for the first round of a presidential election which could see the end of two decades of centre-left rule since Augusto Pinochet relinquished power in 1990.Centre-right billionaire businessman Sebastian Pinera is 10 points ahead of his nearest rival in the opinion polls. Political analysts are forecasting victory for the man whose campaign has been based on a promise to build on prudent fiscal policies that have made Chile the world’s number one copper producer and a regional model of stability. But his ratings do not look good enough to clinch an outright victory. Support for Pinera is said to stem from widespread disillusionment with the current administration which critics say, has not done enough to spend the copper dollars on social programmes. His main rival, Eduardo Frei, is seeking a second-term as president after an absence of 10 years. He is the candidate most likely to force a run-off vote if he can stop Pinera acquiring 50 per cent of the vote. If that happens observers say Frei will then form a pact with another leftist candidate to block a second round Pinera victory.