NewsX: In a major boost to Narendra Modi in the party's prime ministerial race, the BJP today swept the six bye elections to Lok Sabha and Assembly seats in Gujarat while his detractor Nitish Kumar suffered a blow in Bihar and Congress drew a blank in four states. Lalu Prasad Yadav congratulated Gujarat CM Narendra Modi for winning again. He also slammed Nitish Kumar who lost by poll with a great margin.