LONDON (AFP) - British 12-month inflation surged to a 16-year high point of 5.2 percent in September owing to soaring energy bills, official data showed on Tuesday but analysts said it would plunge in the coming months. Consumer Prices Index (CPI) annual inflation " the government's target measure " had stood at 4.7 percent in August, the Office for National Statistics (ONS) said in a statement. September's level was the highest since March 1992, when it came to 7.1 percent. Analysts' consensus forecast had been for a rise to 5.0 percent, while the government has a target rate of 2.0 percent for annual inflation. "Despite September's bigger-than-expected jump, consumer price inflation is almost certainly now at its peak, or very near to it," said Howard Archer, chief Britain economist at the Global Insight consultancy in London. "Indeed, consumer price inflation should soon start falling back sharply and we believe it could well be back down to its 2.0pc target level by the end of 2009." Archer added: "Prolonged very weak economic activity, faster rising unemployment and extended tight credit conditions will increasingly dilute underlying inflationary pressures (...) In addition, available evidence clearly points to wage moderation continuing. "Meanwhile, the recent marked retreat in oil and commodity prices will obviously help matters," said the economist. The ONS added on Tuesday that Britain's consumer prices index had risen by 0.5 percent in September on a monthly basis, down from 0.6 percent in August. Analysts had forecast a rise of 0.4 percent. "The key issue now is just how far and fast inflation will drop back as the food and energy effects which have pushed it up so sharply over the last year finally fade or go into reverse," said Jonathan Loynes, chief European economist at Capital Economics. "Inflation should be back below four percent by the end of the year and then start to drop very sharply next spring. "By the autumn (of 2009 in Britain), we expect it to have fallen to 1.0 percent but it could go lower " and even turn negative " if oil prices fall much further." Electricity price inflation rose to 30.3 percent year-on-year, up from 18.0 percent in August, said the ONS. Gas inflation rose to 49.9 percent, up from 27.7 percent in August, noted the statistics office. "The largest upward pressure on the CPI annual rate came from housing and household services because of rises in average gas and electricity bills this year compared with falls last year," the ONS said. Sterling jumped against the dollar and euro on foreign exchange markets following release of the inflation data. The Bank of England had forecast in August that inflation was set to rise sharply to around 5.0 percent this year, before declining rapidly toward the government's target of 2.0 percent from early 2009. Its prediction had been based on interest rates remaining at 5.0 percent. However, last week the Bank of England unexpectedly decided to slash British borrowing costs by a half-point to 4.50 percent in an emergency rate-cutting drive by major central banks around the world. Britain's biggest rate reduction for seven years came as the country faces the growing threat of a recession " two or more quarters of negative economic growth " amid a global financial crisis.