"The hike in rail fares across the board was a sound economic decision and should not be politicised. The fares have not been hiked for 10 years," Chidambaram told reporters after a cabinet meeting.
Railway Minister Pawan Kumar Bansal, announcing the fare hike Wednesday, said the increase would be effective Jan 21 midnight.
The opposition including the Bharatiya Janata Party, Left parties and Trinamool Congress had said the hike was anti-poor.
"It is a fair game for the opposition to oppose the hike for the sake of opposition," said Chidambaram.
He said the fares had not been hiked since the time of then railway minister Nitish Kumar in 2003.