Union minister Ramdas Athawale has been slapped by a man at a public event in Maharashtra's Ambernath town, police said.The man, who allegedly slapped the Republican Party of India (Athawale) chief, has been identified as a worker of RPI(A) youth wing. The incident took place Saturday night as the Minister of State for Social Justice and Empowerment was coming down from the stage, a police official said. The accused has been identified as Pravin Gosavi. He was later beaten up by Athwale's supporters. Gosavi has been shifted to the state-run J J hospital in Mumbai after receiving initial treatment in Ambernath, police said. The motive behind the attack was not known and police are investigating the matter. On Saturday, scores of RPI(A) workers assembled outside Athawale's residence with party flags, protesting against the incident.