PNC secured the highest number of elected members this election; 15 of them are at the Alotau camp. It is understood they have 24 elected MPs.
Electoral Commissioner Patilias Gamato, at the return of writs to the Governor-General at 4pm today, advised Sir Bob to invite PNC to form government.
Parliament will sit next week to elect a speaker and eventually, a prime minister.
President of PNC party, Joseph Kup, was present at Government House today at the presentation of the writs.
A total of 80 writs out of the 111 that were issued on April 24 were given to the head of state.
Commissioner Gamato said as of this morning, 88 electorates were declared but only 80 writs were presented to him by the respective returning officers.
He said the remaining writs should be returned on Monday afternoon.
Meanwhile, there is confusion as to the exact date when parliament will sit.