Leader of the Opposition Suryakanta Mishra said the police had been ''instructed and misused'' by the state government to gag voice of the opposition.
Left Front sources said that the rally, proposed to be held in front of the city civic body headquarters, was planned to highlight state government's 'failure' to combat dengue outbreak in the city and some districts as also 'corrupt deals' in the installation of trident lamp posts in municipal corporation areas in the metropolis.
They alleged that the police did not delay in giving permission to a rally addressed by Chief Minister Mamata Banerjee but had taken a 'rigid stand' in case of the opposition parties on the 'plea' of law and order.
"We will hold the rally despite the police disallowing any such meeting at the venue on October 9," they added.
Police authorities were, however, not available for comment.
