ISLAMABAD      -     The major parliamentary opposition parties are contemplating to forcing the PTI government to summon the national assembly and conduct elections on vacant seat of deputy speaker. The joint opposition parties (PPP-P, PML-N and JUI-F) will soon start work to submit a requisition in the national assembly secretariat for the session, background discussion with opposition parties’ members revealed. The Election Commission of Pakistan (ECP) a couple of days back had de-notified Qasim Khan Suri, elected from Balochistan, as deputy speaker. The election tribunal had announced that thousands of unverified votes had led to his victory. Sources said that the opposition parties would field a consensus candidate for the vacant post of deputy speaker and will jointly submit a requisition. The sources said that the opposition has planned to force speaker national assembly to conduct election on the vacant seat of deputy speaker.