He alleged that the Congress was "deceiving" the people over the issue of reservation, while the agitators were lining up for poll tickets.
Patel quota agitation leader Hardik Patel's open support to the Congress in the December Assembly polls is not an electoral alliance but a "deal" between two sides, Mr Rupani told news agency PTI in an interview.
Dubbing Congress vice president Rahul Gandhi, who is extensively campaigning in Gujarat, as "gappidas" (teller of lies), the chief minister accused him of dishing out fabricated statistics about the BJP-ruled state.
"From what I understand, I can say it (Congress-Hardik Patel alliance) won't have any effect (on the BJP) as they are exposed. They have kept aside the original demand of reservation and agitators have lined up to get Congress tickets," he said.
Mr Rupani was replying to a question on the impact of Hardik Patel pledging support to the Congress in the Gujarat polls.
"While the Congress is not speaking a word on how it will give reservation to the Patidars (if it comes to power), he (Hardik Patel) is declaring support to the Congress. This shows there is 'saudebaazi' (deal) (between them)," he claimed.
"The Congress formula on giving reservation above the 50 per cent cap is an attempt to deceive the people and it won't work. This exposes the deal," he further said.
"As the opposition does not have any issues against us they are taking refuge in casteism. The Congress is outsourcing its campaign by bringing in symbols of casteism like Hardik Patel, Alpesh Thakor (OBC leader), Jignesh Mevani (Dalit activist) and tribal leader Chottu Vasava," Mr Rupani said.
The 182-member Gujarat Assembly will go to the polls in two phases -- on December 9 and 14. The counting of votes will be taken up on December 18.