ISLAMABAD Pakistan Muslim League-Nawaz (PML-N) leader Ishaq Dar has written a letter to the Prime Minister Yousuf Raza Gilani, demanding that joint session of the parliament be convened instead of National Assembly session and all-party conference on the situation emerging after the security threats issued by the United States. The Prime Ministers House sources confirmed the PMs Secretariat has received the letter from Senator Ishaq. In that letter the PML-N leader has said that the present situation makes it essential for the government to take all the political forces in confidence and devise a consensual strategy to meet the challenge to the national security after US threats by calling a join session of the two Houses of the Parliament. He maintained in the letter that the briefing by the top US defence officials Leon Panetta and Mike Mullen was meant to increase the morale of US troops in Afghanistan. According to him, Panetta and Mullen were responsible for the lack of security and protection for US troops in Afghanistan. Earlier, President Asif Ali Zardari had summoned National Assembly session on Oct 3 while the PM has called an all-party meeting over the issue. A private TV channel reported that high security officials have requested the government to arrange in-camera briefing on the current situation. On the other hand, PML-N President Nawaz Sharif summoned a meeting of senior party leaders on Tuesday to form a party policy on the issue after consolations.