Gangster-turned-politician Mukhtar Ansari, who was earlier with the Samajwadi Party (SP), joined the Bahujan Samaj Party (BSP) on Thursday. Mukhtar's son has also joined the party ahead of the Uttar Pradesh Assembly polls, BSP supremo Mayawati said. While Mukhtar will be contesting for BSP from Mau Sadar, his son Abbas Ansari will contest from Ghosi.