There had been rumours for the past couple of weeks that Shatrughan may join Congress. Annoyed with Shatrughan for his constant criticism of PM Modi and his government, BJP denied him a ticket and, instead, fielded Union minister Ravi Shankar Prasad from Patna Sahib. Both Ravi Shankar and Shatrughan Sinha are from the Kayastha caste.

from Times of India https://timesofindia.indiatimes.com/india/its-official-shotgun-to-join-congress-this-week/articleshow/68570685.cms