Senior RJD leader and former union minister Raghunath Jha and Janata Dal-United (JD-U) leader Ram Jeevan Singh have joined the Samajwadi Party, it was announced on Thursday.Jha, who was the national vice president of the Rashtriya Janata Dal, resigned from its primary membership, Samajwadi Party president Ramchander Singh Yadav told the media.Jha said he resigned from the RJD after being sidelined and ignored by RJD leader and former chief minister Lalu Praaad.A former Bihar minister, Ram Jeevan Singh also joined the Samajwadi Party after resigning from the JD-U.Both Jha and Singh joined the Samajwadi Party after it quit the "grand alliance" of JD-U and RJD and decided to contest the coming Bihar assembly polls on its own.