Sudhakaran is the CPI-M legislator from Ambalapuzha constituency. Pitted against him in the assembly elections of Monday was Janata Dal-United (JD-U) leader Sheikh P. Harris of the Congress-led UDF.
Alappuzha district Congress committee president A.A. Shukoor told the media here that a veteran of election battles like Sudhakaran had violated basic election rules.
"We have registered our complaint with the Election Commission as he peeped into the compartment not once but twice when Achuthanandan and his wife voted on Monday," said Shukoor.
Sudhakaran said he had done no wrong, and demanded to know why the police allowed journalists into the voting centre. He said he was ready to face the legal issues.