Banerjee, also the West Bengal chief minister, was the main speaker at a rally against FDI in multi-brand retail in New Delhi on October 1.
She is also slated to visit other states to drum up support on the issue.
Bhattacharya, a Rajya Sabha member, said FDI in retail would benefit the state and those opposing it were helping middlemen and jeopardising interests of marginal farmers and traders.
"The reform seeks to eliminate middlemen, but the state government and the Left Front, by opposing it, are strengthening touts," he said.
"If FDI is such a harmful thing, why did Jyoti Basu or Buddhadeb Bhattacharjee (former chief ministers) go to foreign shores to invite investment? Why Banerjee as the railway minister procured foreign machineries?" he said.