Pakistan Tehreek-e-Insaf (PTI) terminated on Saturday the membership of 22 leaders, including former Punjab chief minister Mahmood Khan.
The development came after Khattak formed the breakaway faction, PTI parliamentarians. Other leaders who had been expelled from the party were Shafiq Afridi, Ziaullah Bangash, Ishtia Urmar, Iqbal Wazeer, Yaqoob Sheikh and Wilson Wazeer.
The notice was issued by PTI secretary general Omar Ayub Khan to the defected members.
Earlier this month, Khattak formed his own political party after parting with the original party.
The party had been named Pakistan Tehreek-e-Insaf (Parliamentarians), and Khattak will be its head.
The party membership of Khattak had been revoked. For not responding to the show-cause notice, the PTI had taken action against Khattak. Khattak's basic membership was terminated, according to a notification from PTI Secretary General Omar Ayub Khan.
Earlier, the PTI issued a show-cause notice to Khattak for allegedly inciting members to leave the party.