The challenge, announced by the Election Commission to counter allegations of EVM tampering levelled by parties such as Aam Aadmi Party (AAP) and Bahujan Samaj Party (BSP), will be held on June 3 between 10 am and 2pm.
He said a total of eight parties had responded to EC's letter of invitation for the June 3 event.
"NCP expressed interest in participating in the EVM challenge. AAP and Congress raised some issue as per the existing framework of challenge but have not expressed their interest in participating."
"The CPI, CPI(M), BJP and RLD expressed their interest to observe (the challenge)," he said.
The All India NR Congress wrote that it will not participate in the challenge, the spokesperson said.
On Saturday last, the Commission had announced that the challenge to hack and tamper with the electronic voting machines (EVMs) would take place on June 3 and the seven recognised national and 49 state parties can apply till this evening to participate in the challenge.
After the Uttar Pradesh assembly polls, the BSP and AAP had questioned the reliability of the machines.
Later, several opposition parties, except the AAP, had urged the EC to revert to paper ballot, saying the faith of the people in EVMs has eroded.
A demand of the AAP to tamper with the motherboard of the machine was rejected by the Commission. It said change in circuits would mean the EVM is no longer the one used by the Commission.