The protest was inaugurated by CPI(M) state secretary, Kodiyeri Balakrishnan.
CPI Secretary Kanam Rajendran, Janata Dal (S) Secretary George Thomas, Congress (S) state chief and state Ports Minister Kadanapally Ramachandran, were among those who participated.
LDF has been organising a series of protests since the past few days against the Union government's decision to bring down the state's rice quota.
"Even as the left front is trying to intensify its agitation demanding restoration of the rice quota of the state, the Centre was trying to destroy the statutory rationing system," the LDF leaders alleged.