A group of delegates to Afghanistan\'s historic loya jirga is set to claim the constitution they approved earlier this month was altered by the government ahead of its signing into law. The group of about 20 delegates from the capital Kabul is headed by Abdul Hafiz Mansoor, a former anti-Soviet mujahedin fighter and head of the opposition bloc at the loya jirga (grand assembly) that opposed many of the arguments put forward by the government of President Hamid Karzai. \"I myself have discovered more than 15 changes that the government does not have the authority to make,\" Mansoor told AFP. The new constitution was approved unanimously by the 502 delegates to the loya jirga on January 4 after three weeks of intense debate and finally signed into law by Karzai Monday. It enshrines a presidential system of government backed up by a strong bicameral parliament and paves the way for Afghanistan\'s first democratic elections later this year. The opposition bloc, which also includes loya jirga delegates from Kabul\'s surrounding provinces, intends to voice its opposition at a press conference in the capital on Wednesday. \"The constitution which was signed by President Karzai, if it is carefully read... compared to the constitution approved and ratified by delegates to the loya jirga has changes,\" Mansoor told AFP Tuesday. \"After the end of the loya jirga nobody has the authority to change what is in the constitution, but now in the constitution after the loya jirga there has been lots of changes. Mansoor says changes were made to the wording in sections that covered official languages, presidential powers and duties and the administration. Mansoor has previously said that his bloc would have a candidate ready to contest the presidential elections, scheduled for June. (AFP)