"September, October and November would be months of agitation by Congress," KPCC president R V Deshpande and Leader of Opposition in the Legislative Assembly Siddaramaiah told a joint press conference in Bangalore on Thursday.
The rallies would not only highlight the illegal mining issue, but also the need for a CBI probe into it and "failures" of the government, they said.
The Congress' move comes three days after it concluded its 320 km padayatra from here to mine-rich Bellary district against the BJP government, with the spotlight on illegal mining.
The party had embarked on the 'Nadarakshana Nadige (save the state walk)' targetting ministers K Janaradhana Reddy and his brother Karunakara Reddy, mining magnates from Bellary, after accepting their challenge in the state Assembly to set foot on their home district.
During the three-month agitation, the party would also interact with those affected by last year's floods in many districts of the state, listen to their grievances, take up their cause and press the government to solve their problems, the Congress leaders said.
"The Chief Minister is involved in the loot (of illegal mining)," Deshpande alleged.
Siddaramaiah referred to power cuts in the state and said farmers have been left in the lurch.
"Yeddyurappa says he is helpless that he can't give power. He should somehow purchase power and provide it. Otherwise, he should resign," he said and charged the government with "financial indiscipline".