President Asif Ali Zardari neutralized the July 7 ruling of the Supreme Court in which a heavy carbon surcharge on petroleum products was declared null and void and imposed the same amount of tax through a law on Thursday. The prices of petrol, diesel, kerosene oil, light speed diesel and HOBC were again increased with immediate effect. The prices of these items had been reduced because of the suspension of carbon tax by the Supreme Court. The president issued an ordinance on the advice of Prime Minister Yousuf Raza Gilani to mobilize Rs122 billion that was to come in the national kitty through the carbon tax. The petrol price went up by Rs10 per litre, diesel by Rs8 per litre, light speed diesel by Rs 3 per litre and HOBC by Rs 14 per litre. Officials of the ministries of law and petroleum and Federal Board of Revenue finalized the ordinance. The presidential ordinance would remain effective for 120 days unless it was passed by parliament before it. After its parliamentary approval, it would become an act of parliament but till than it would also remain a piece of legislation. Justice Nasir Aslam Zahid said the ordinance could be challenged in the Supreme Court.