Six Left parties on Friday sought the release of JNU student leader Kanhaiya Kumar and punishment to those who they said fabricated "evidence" leading to his arrest for sedition.
Kanhaiya Kumar's arrest on charges that he shouted anti - national slogans during a meeting on Kashmir in the campus was "part of efforts to sharpen communal polarization in the country", they said.
The joint statement was issued by the Communist Party of India - Marxist, Communist Party of India, Revolutionary Socialist Party, All India Forward Bloc, Communist Party of India - Marxist - Leninist - Liberation and Socialist Unity Centre of India - Communist.
"Kanhaiya Kumar must be released and all cases of sedition filed against students must be withdrawn forthwith. No harassment and witch hunting must be allowed, " it said.
"The truth has now come out that most of the evidence produced by the government was fabricated. Those who have fabricated the evidence and propagated it must be punished under the law. "
The Left parties said they condemned the attack "launched by the RSS - BJP against the Left and all other progressive forces".
They said the denunciation of the Jawaharlal Nehru University (JNU) was "part of a larger design by communal forces to carry forward their agenda in institutions of higher learning".
The Left parties will hold all - India protests from February 23 to 25 on this issue, it said.