Banerjee said in a Facebook post that the increase of FDI in telecom to 100% would have "very serious" security implications for the nation and enable foreign companies control the country's entire telecommunication platform.
As defence was heavily reliant on telecommunication system, the new arrangement would compromise safety and security of the nation, the Trinamool Congress president charged.
"It is a myth that FDI hike will bring transfer of technology to Indian companies as there is a 'Technology Denial' regime which does not permit the developed world to transfer defence technology," she said.
Banerjee attacked the UPA government for liberalising insurance sector too, saying "the lives of poor and common people, who rely on insurance for their life and health, will be put to risk with increase in FDI in insurance sector."
Foreign inflow of funds in financial institutional area in India was fraught with potential danger of global financial crisis, she said.
The central government today liberalised FDI limits in a dozen sectors, including allowing 100% in telecom, and higher limits in 'state-of-the-art' defence manufacturing.
The Centre also decided to raise the FDI cap in insurance sector from 26% to 49% under automatic route under which companies investing do not require prior government approval.