CPM General Secretary Prakash Karat has accused the Congress of "not raising its voice against communal forces".
"Congress, which is in Opposition in BJP-ruled states, is not raising its voice against injustice, like in Gujarat where Muslims are being treated like second-class citizens", Karat said addressing a public meeting in Mumbai on Monday night.
"We have fought against Congress all our life, before and after Independence. Our relationship with that party is based on the single-point agenda of combating communal forces", he said.
He pointed out that in states like Kerala, West Bengal and Tripura, where Left was in power, "there is not a single BJP MLA".
"We demand that the UPA government combat communal forces effectively", he added.
"The country needs another alternative. CPM will work towards forming that alternative", Karat said, explaining the objective of the party's ongoing national campaign to propagate its policies.
Over 200 public meetings would be held in the country as part of the campaign, Karat said.
"I have so far addressed meetings in four states and would visit 10 to 12 more states by September-end", he said.