Shatrughan Sinha had quit the BJP to join Congress.
Acharya Pramod, Congress candidate from Lucknow took strong exception to party leader Shatrughan Sinha campaigning for his wife Poonam, who is the Samajwadi Party candidate in the constituency.
"From the behaviour of Shatrughan Sinha, it appears that although he has joined the Congress, but has not yet resigned from the RSS," Mr Pramod tweeted.
Shatrughan Sinha was by his wife's side when she filed her nomination papers for the seat. The actor-turned-politician attended an election meeting on Thursday with Samajwadi Party president Akhilesh Yadav.
He had the BJP recently and switched over to the. Congress. He will contest elections from the Patna Sahib constituency in Bihar.
Poonam Sinha is the SP-BSP-RLD alliance candidate from Lucknow, who is contesting against Union Home Minister Rajnath Singh and Acharya Pramod.
Lucknow will vote in the fifth phase of the Lok Sabha elections on May 6.