The Solomon Islands opposition is demanding to know why the Prime Minister has invited leaders from the PNG island of Bougainville to this year's Melanesian Spearhead Group Leaders' Summit.
Alfred Sasako says Sir Allen Kemakeza has greatly offended Papua New Guinea with the move.
He says the Prime Minister extended a verbal invitation to one of the Bougainville leaders in Honiara recently which was followed by a formal invitation to the MSG later this year.
Mr Sasako says Sir Allen's invitation gives Bougainville a recognition of entity when it is an integral part of PNG.
He says it ignores years of hard work which have been put in to help end the civil war and he hopes it's not the prime minister's intention to ignite ill-feelings between the Port Moresby government and the interim authority on Bougainville.
Mr Sasako says he believes Papua New Guinea has taken retaliatory measures, including cancelling a planned visit to Port Moresby next week by Foreign Minister, Laurie Chan.
The MSG summit is being hosted by Solomon Islands this year.