Sept. 7 (Bloomberg) -- Thailand central bank deputy governor Atchana Waiquamdee said the bank may need to revise down its economic growth forecasts if political unrest persists.

``Up until now we don't think that it's going to have an impact on our growth forecast, but if it is prolonged, especially in the high season of tourism, then we have some impact,'' Atchana told reporters today in Basel, Switzerland, where she's attending a meeting at the Bank for International Settlements. The bank currently expects 2008 economic expansion between 4.8 percent and 5.8 percent.

Thai Prime Minister Samak Sundaravej reiterated today that he won't resign as the government prepares a plebiscite aimed at ending a standoff in which protesters demanding he quit have occupied his office for 11 days. A state of emergency remains in place in Bangkok after deadly clashes on Sept. 2 between pro- and anti-government protesters. The crisis has undermined Thai stocks and caused a slide in the nation's currency.

Atchana reiterated that the central bank will ``step in'' if needed to reduce exchange-rate volatility.

``We don't have any target for the baht,'' she said. ``When it's very volatile, the central bank will step in, but we have the market determine the value of currencies.''

To contact the reporters on this story: Belinda Cao in Basel at lcao4@bloomberg.net; Joshua Gallu in Basel at jgallu@bloomberg.net

Last Updated: September 7, 2008 12:32 EDT