"The CPI will support Hamid Ansari in the vice presidential election," the party's National Secretary D Raja told PTI after a CPI central secretariat meeting in New Delhi.
The CPI has become the third among Left parties to back 75- year-old Ansari after the CPI-M and Forward Bloc extended support to him for the August 7 poll. The Revolutionary Socialist Party has decided to abstain in both the elections.
The CPI has six MPs in both Houses of Parliament. The CPI-M has 27 MPs, Forward Bloc three and RSP two.
The UPA is comfortably placed in the electoral college for the vice presidential poll comprising 790 MPs. Ansari has the support of Samajwadi Party, the Bahujan Samaj Party and others.
The RSP has decided to abstain in both the presidential and vice presidential elections on the grounds that it could not support a UPA candidate as it was opposed to the policies of UPA-II government.