Speaking in the Solomons parliament Monday, Manasseh Sogavare said Fiji should apologise for bringing Indonesia into the MSG.
He said Fiji's Prime Minister Frank Bainimarama breached MSG procedure by forcing the other four full members to accept Indonesia as part of the sub-regional grouping, whose full members are Papua New Guinea, Fiji, Solomon Islands, Vanuatu and FLNKS Kanaks movement of New Caledonia.
Indonesia was admitted to the MSG with observer status in 2011 after Bainimarama assumed the MSG's rotational chairmanship.
“There was no consensus in the admission of Indonesia by member countries,” claimed Sogavare who wants Indonesian control of West Papua reviewed by the United Nations.
In 2015 Indonesia had its status in the group elevated. This remains a complicating factor as the MSG wrestles with the sensitive issue of a West Papuan membership bid.
However, in response, Fiji's Defence Minister Ratu Inoke Kubuabola, who often represents Fiji at MSG summits, denied Sogavare’s claim that the MSG didn't reach consensus on the issue.
“I think he is either suffering from memory loss or trying to play politics with his own constituents,” said Ratu Inoke.
“He has forgotten that it was during his term as chair of the MSG when Indonesia was admitted to the MSG as an associate member. All members of the MSG had agreed.”
Sogavare had chaired the 2015 meeting in Honiara where, according to Ratu Inoke, MSG leaders reached consensus about Indonesia's status in the group.
“I cannot really understand why he is making this statement, trying to put the blame on our prime minister, because all the (MSG) members agreed to admit Indonesia as an associate member,” said the Fiji minister.
Following the 2015 summit, Sogavare spoke of how bringing Indonesia into the fold had been polarising for MSG leaders.
The United Liberation Movement for West Papua was itself granted observer status in the MSG in 2015, but its application for full membership continues to divide the five full members.
At their latest summit in Port Moresby last month, MSG leaders approved new clarifications on guidelines around membership in the group.
The Liberation Movement's application has been referred to the MSG secretariat for processing, but Fiji and Papua New Guinea have signalled they remain opposed to the pro-independence West Papuans being given full membership.
Of the other full members of the group, Vanuatu and the FLNKS appear firmly in support of the Papuan bid.
Solomon Islands had until recently also been strongly in support of giving West Papuans full membership in the MSG. But when Mr Sogavare was ousted as prime minister late last year, and replaced by Rick Hou, that support appeared to dim.
The position of PNG and Fiji on the West Papua membership issue had been “really clear”, according to Ratu Inoke.
“And the new prime minister of Solomon Islands, in the last meeting in Port Moresby, about three weeks ago, took a similar position,” he said.
Sogavare however remains a strong influence in government, and his stand on the Papua issue appears unlikely to diminish.
“Close association of Fiji with Indonesia is sabotaging the work of MSG and their membership in MSG is not political but economic interest,” said Sogavare.
Echoing recent statements by Vanuatu's government, Sogavare said the MSG's founding aim of working to decolonise all Melanesian peoples was at risk.