Australia's acting High Commissioner in Fiji is expected to be formally expelled from the country today.
It is understood Sarah Roberts will be served with a notice and given 24 hours to leave Fiji.
The foreign affairs minister, Stephen Smith, says the expulsion is linked to the postponement of the Melanesian Spearhead Summit because of concerns about Fiji's role as chair.
He's called the decision unjustifiable.
"I'm not proposing to respond in kind, I would regard that as effectively leading to a breakdown of completely and professional diplomatic relations between Australia and Fiji."
Australia's foreign minister, Stephen Smith.
Fiji's foreign affairs minister Ratu Inoke Kubuabola says the expulsion of Sara Roberts is a direct result of recent reports she has been interfering with the internal affairs of Fiji and conducting unfriendly acts.
Fiji Village reports Ratu Inoke says Fiji had on numerous occasions relayed its concerns to the Acting High Commission.
He says the Australian government has been engaged in strategies to undermine Fiji's sovereignty and weaken the economy.
Meanwhile, Fiji's interim Prime Minister has accused Australia and New Zealand of being behind the cancellation of next week's Melanesian Spearhead Group summit.
The deferment came from Vanuatu's Prime Minister and the current chairman of the MSG Edward Natapei who indicated that an impasse over Fiji's hosting and chairmanship of the event needed to be resolved.
The Fiji Sun reports that Commodore Frank Bainimarama says Mr Natapei was pressured by Australia and New Zealand who are on a mission to dissolve the MSG.
He says Mr Natapei was the only MSG member opposing the chairmanship despite several proposals by Papua New Guinea and Solomon Islands.
He says this is because they understand Fiji's role in the Summit.