In the last 50 days, there has been a mass exodus in the Rajya Sabha. Nine MPs have crossed over to the BJP. The defections have ensured that BJP's Rajya Sabha gap narrows down. NDTV spoke to Trinamool Congress's parliamentary party leader in the Rajya Sabha, Derek O'Brien on what he thinks is the reason behind the defection of these MPs. "Before MPs join, they are put into this proverbial spa. All their sins and all their CBI cases are washed away," he said.