Prime Minister has written to PAC Chairman Murli Manohar Joshi, saying he is ready to appear before it in connection with the 2G spectrum issue. Dr Manmohan Singh said earlier that he had nothing to hide in the 2G scam and was ready to appear before the Public Accounts Committee of Parliament. His remarks came against the backdrop of a winter session of Parliament that was dominated by the Opposition's demand for a Joint Parliamentary Committee probe into the 2G scam and the Supreme Court opting to monitor the probe.