The stage is set for a showdown in Singur with Mamata Banerjee followers who have laid siege around the Nano plant announcing they won't allow any employee to enter the factory from Friday. The announcement came from Naxalite leader Purnendu Bose, now one of the partners of the Krishi Jami Raksha Committee. Bose is among the several leaders of Trinamool allies who have pitched in their lot with her campaign against the Tata plants. He was one of the leaders nominated by Mamata to sit for talks with the government on August 20. The armtwisting tactic is aimed at forcing the state government to accept Trinamool demand of returning 400 acres of land, which the party claims was forcibly taken from farmers. But it is likely to heighten fears about security, which Ratan Tata has said, could force him to pull out the Rs 1,500 crore investment from West Bengal. However, a Tata spokesman said the company was hopeful the agitators would review their decision. Biman appeals to Mamata for talks to end stir Singur: The heightening of tension by protesters at Singur, who had so far blocked the highway leading to the plant, also indicated that Trinamool may have lost control of the movement in Singur and ceded ground to more hardline groups like SUCI which won't compromise on land return and don't care about industry. Left Front chairman and CPM state secretary Biman Bose accused the agitators of reneging on their promise of a