With the banking system liquidity slipping into a deficit, the Reserve Bank of India (RBI) will conduct an overnight variable rate repo auction for Rs 50,000 crore on Thursday. Banks have been borrowing increasing amounts from the marginal standing facility (MSF) window over the past week or so — on Tuesday they borrowed a little over Rs 30,000 crore, up from Rs 11,000 crore on Monday. Moreover, over the past few sessions, the call money rate has slowly crept past the repo rate — it was 5.6% on Monday and inched up to 5.64% on Tuesday.