New Delhi, April 30 (ANI): Tainted BJP leader Bangaru Laxman today served his resignation to the party president Nitin Gadkari, after a CBI Court, on Saturday sentenced him to four years in prison for taking a bribe of Rs. 1 Lakh in the infamous Tehelka sting operation.BJP had earlier dropped its former party President Laxman, within hours when the expose had come into light.