Jharkhand Mukti Morcha (JMM) supremo Sibu Soren's younger brother Lalu has joined Mamata Banerjee's Trinamool Congress.
"On February 27, we attended a party meeting at Trinamool Bhawan in Kolkata. Senior party leader Mukul Roy welcomed the decision," said Jharkhand state president of TMC's women cell Munni Hansda on Saturday.
JMM central general secretary Supriyo Bhattacharya claimed the move would not impact JMM's campaign.
"This is nothing but a political drama," he told Hindustan Times.
Lalu Soren was reportedly in Bokaro and could not be contacted for comments.
Trinamool Congress has been building its base in the bordering areas of West Bengal, including Dumka, Pakur, Jamtara and Sahebganj for the last five years.
In Dumka, Hansda had launched an agitation against the RPG Group for installation of a 1,000 MW power plant in the Kathikund block in 2008.
She has been working for Trinamool Congress for some years now.