The 30-share BSE Sensex rallied over 400 points and the 50-share NSE Nifty hit 5700 level in the noon trade today as the UPA government stood strong with support by Mulayam Singh Yadav's Samajwadi Party.Sensex was trading 427 points up at 18,776 points, a shortwhile ago. It recovered by almost 149 points in early trade today on buying by funds and retail investors after the government notified its decision to allow FDI in the multi-brand retail sector. The 30-share barometer had lost nearly 193 points in the past two sessions.Nifty was also trading 139 points up at 5,693 points a shortwhile ago.