Awami Muslim League (AML) chief Sheikh Rashid is Khan's nominator for the post, while Fakhar Imam is the guarantor.
Khan was nominated as the PTI 's pick for PM during a meeting of senior party leaders at Banigala.
Other parties have yet to submit their nominees for the office.
A 11-party opposition alliance, comprising the PML-N, PPP and others, had earlier unanimously accepted PML-N President Shahbaz Sharif as their nominee for the post, but later the, PPP expressed reservations over the nomination.
Earlier, Asad Qaiser was elected as the speaker of the NA. He defeated former opposition leader in the National Assembly Syed Khursheed Shah of the PPP.
Asad Qaiser received 176 votes to be elected to the speakership, whereas Shah got 146 votes. A total of 330 votes were cast, out of which 322 were accepted and eight were rejected. Outgoing speaker Ayaz Sadiq administered the oath to the newly elected Speaker.
The newly elected Speaker is chairing the session the election for the slot of deputy speaker is underway.
Qaiser, who previously served as speaker for the Khyber Pakhtunkhwa Assembly, won NA-18 Swabi I and PK-44 Swabi 2 constituencies on the PTI 's ticket during the July 25 General Election.