The Election Commission, the CPI said, informed it about its stand that the party cannot observe the EVM challenge programme only yesterday.
"Being a national party we wanted to witness the challenge. But surprisingly, it told us we cannot take part in the process, but only those parties which took part in the challenge. This is deplorable," CPI General Secretary S Sudhakar Reddy said over the phone.
In a letter to the Commission written yesterday, Mr Reddy said the CPI wanted to witness the process in the interest of transparency for the healthy traditions of democracy.
"We are of the strong opinion that this approach of secrecy in such an exercise is in contravention to the spirit of your invitation letter seeking cooperation from political parties. It raises doubts about the motive of Election Commission behind this denial," the leader said.
The Election Commission has been the target of attacks from political parties over its voting machines. Only two parties, the Nationalist Congress Party and the CPI-M had applied to participate in today's EVM challenge conducted by the commission to put all concerns about the machine's reliability at rest.