Ruling out a Joint Parliamentary Committee probe into the 2G spectrum scam, Finance Minister Pranab Mukherjee today appealed to the opposition parties to let Parliament function so that a debate on the issue could take place. Talking to reporters in Kolkata, he said, he has requested the opposition to come back to the House and let the whole issue be debated in Parliament. Let them say whatever they want to say on the floor of the house and the government will respond, said Mr. Mukherjee.