"Slit my throat but no one tells me what to do," a defiant Mamata Banerjee declared today after a court said her government in Bengal cannot ban the immersion of Durga idols on Muharram and cancelled the unusual restrictions that she had ordered on grounds that there could be trouble. "You are exercising extreme power without any basis," the Calcutta High Court said in sharp comments on the order banning immersions after 10 pm on September 30 - when Durga Puja ends - and on Muharram a day later.