The benchmark Sensex tumbled by 432.15 points after a brief surge during morning trade on Monday due to heavy selling by investors on possibility of snap polls at the Centre.
The Bombay Stock Exchange (BSE) barometer tumbled 432.15 points to a low of 17,550.44, after touching a new intra-day high of 17,982.59. It was being quoted at 17,562.12 points at 11 am from Friday's close of 17,773.36.
Crediting the Sensex's initial jump by about 209 points to strong global cues, market players said investors reacted negatively in the wake up of deepening political crisis on the Indo-US nuclear deal.
UPA chairperson Sonia Gandhi's had yesterday defended the nuclear deal and said that "elements" opposed to the country's progress were enemies not only of the Congress but also of the nation's development.
Reacting strongly to this, CPI General Secretary A B Bardhan said: "Congress is going to an election mode. Congress wants to impose an election on the country."
Meanwhile, CPI-M is likely to convene a meeting of its Politburo here soon if UPA-Left committee on the deal fails to end the logjam on the issue.
Congress later sought to downplay Gandhi's remarks saying they were not directed at the Left parties.