The Congress on Thursday formally approved its electoral alliance with the Left parties for the assembly elections in West Bengal, party's state unit chief Adhir Ranjan Chowdhury announced.
The West Bengal PCC had earlier recommended an alliance in favour of the Left parties.
The Left parties had also favoured an alliance with the Congress for the state elections.
"Today the Congress high command has formally approved the electoral alliance with the Left parties in the impending election of West Bengal," Chowdhury said on Twitter.
The Left and Congress did not contest the Lok Sabha elections in Bengal together.
The two parties are also pitted against each other in Kerala.
The West Bengal assembly elections are due by March-April next year.