Here are top 5 points to this big story:
RPN Singh is a key backward caste leader in eastern UP and offsets the loss of Swami Prasad Maurya in the BJP.
Mr Singh has won multiple elections from eastern UP.
He was an MLA thrice from Padrauna and was elected an MP from Kushinagar.
Mr Singh defeated Swami Prasad Maurya in the 2009 Lok Sabha election
For the BJP, the Congress import is good optics after several backward caste leaders quit the party recently.