NA president Simon Kaiwi told local media that the "defectors" had disrespected the party - especially in relation to their support of Nape's controversial decision to dismiss Somare from his East Sepik seat in parliament on Tuesday.
The party-expelled members of parliament have until September 28 to appeal this decision under party regulations Kaiwi told the The National newspaper.
The NA has been a ruling force in PNG's coalition governments for nine consecutive years and its political representation is reportedly down to 21 members after this split.
Poyle told the Post-Courier that the NA constitution had been breached.
On why he and the other NA MPs helped form the O'Neill government last month while Somare remained on medical leave as prime minister, Poyle reportedly said they were "fed up" and could not condone corrupt practices anymore.
Meanwhile, various East Sepik leaders are busy lobbying in Port Moresby for an immediate by-election for Somare's seat - and the grand chief is widely expected to be returned to office.
The National listed the expelled NA MPs and their seats/portfolios:
- 1. Jeffery Nape - Parliament Speaker (Sinasina-Yongomugl)
- Don Polye - PNG's Treasurer (Kandep)
- Ano Pala - Foreign Affairs (Rigo)
- Mark Maipakai - Labour & Industrial Relations (Kikori)
- Charles Abel - Commerce, Industry & Trade (Alotau)
- Lucas Dekena - Lands & Physical Planning (Gumine)
- Andrew Mald - Community Development (Moresby Northeast)
- Sai Beseo - Correctional Services (Kainantu)
- Sali Subam - Sports (South Fly)
- David Arore - Higher Education, Science & Technology (Ijivitari)
- Peter Humphreys - Governor (West New Britain)
- Leo Dion - Governor (East New Britain)
- John Luke Critten - Governor (Milne Bay)
- Michael Sapau - Milne Bay (Manus province)
- Alphonse Moroi - Governor (Central)
- James Gau - Governor (Madang, Raicoast MP)