It is very important that the left party, which rules Kerala, makes its position clear on this at the national level, Mr Gandhi said.
The Congress leader's statement assumes significance in the wake of reports that the recent CPI(M) politburo meeting had failed to reach a consensus on whether it should have a political understanding with the Congress and other secular parties against the BJP.
"I want to ask my friends in CPI(M) whether they actually want to fight the fascist forces in the country," Mr Gandhi said.
"It is very important that that they make their position clear at the national level...Why because...not standing against BJP means supporting BJP," he said.
He also asked whether they accept the fact that the biggest challenge to the county is from "the fascist ideas spread by BJP."
The rally was taken out to highlight the "anti-people" policies of the BJP-led central government and the LDF-led state government.
A two-day CPI(M) politburo meet recently discussed two notes - one presented by CPI-M general secretary Sitaram Yechury and the other by his predecessor Prakash Karat- suggesting the political approach it should follow in the coming three years.
According to CPI(M) sources, since the party had not been able to reach any consensus, the draft would be placed before the central committee.