In a severe setback to the Kerala’s Congress-led ruling UDF during the run-up to the May Assembly polls, Excise and Fisheries Minister K Babu resigned on Saturday after a Vigilance court ordered registration of an FIR against him over the charge of taking Rs10 crore bribe from the State’s bar owners. Babu is the second Minister after Kerala Congress (M) chairman KM Mani to quit over the bar bribery scam in less than three months.