He said his decision to leave the party was to protect the neutrality of the Office of the Speaker.
He still remains as the speaker but as an independent candidate.
The speaker had been accused on social media over fraud allegations made against his office.
During Parliament sitting earlier this month, he announced that he is willing to step aside if investigations are conducted into his office.
During a press conference on Monday, he appealed to the authorities responsible - that is Ombudsman Commission and the National Fraud and Anti-Corruption Directorate - to conduct an investigation.
Pomat said in Tok Pisin: “Kam, buks blong Palamen em i op, kam na sekim mipla. Sapos mipla asua, okay lo i stap, kisim mipla. Sapos mi asua, lo bai mekim sawe long mi na sapos ol wokman blong mi i asua, em tu law i mas mekim sawe long ol." (Parliament books are open so you can come and check if you want. If we have gone wrong then law is there to deal with it).
PNC Party members have moved to the Opposition while Job Pomat remains as an Independent candidate and still maintains his position as the Speaker of Parliament.