Talking to reporters here, Bardhan said the four Left parties CPI, CPI(M), RSP and Forward Bloc have decided to launch nationwide agitation in support of the demand from July to August.
The Left parties would organise dharna at Jantar Mantar in New Delhi for five-consecutive-days from July 30 in support of the demand.
He said the left parties have opposed the present draft of the food security bill.
