Trade unions on Thursday urged Finance Minister P Chidambaram to announce the constitution of the seventh pay commission and raise the income tax threshold to Rs 5 lakh in a year from Rs 2 lakh. The demands were raised at a pre-budget meeting. They also wanted income tax exemption ceiling for the salaried class to be raised to Rs 5 lakh a year and fringe benefits such as housing, medical and educational facilities should be exempted from the income tax net in totality.