The ruling BJP in Bihar suffered a setback on Friday after its candidate for the high-profile July 30 Bankipur Assembly bypoll withdrew at the last minute just a day after filing his nomination papers.Abhishek Sinha, the BJP’s youth wing chief in Bihar, cited family reasons to quit the race for the segment, which fell vacant after BJP president Nitin Nabin resigned following his election to the Rajya Sabha.The BJP had to field another candidate Naveen Kumar today even as Opposition parties took swipes at the saffron outfit, claiming it reflected the ruling party’s nervousness ahead of the bypoll.The seat will see former poll strategist and Jan Suraaj founder Prashant Kishor contest his maiden election.The RJD has fielded Rekha Gupta who secured significant votes when she contested against Nabin in last elections.The last date for filing nominations is July 13.Counting is on August 3.