The International Sugar Organisation, which represents most of the world's sugar producing countries, is holding a key meeting in London this week, to elect a new chairman.
Among those vying for the position is Fiji's interim Prime Minister Commodore Frank Bainimarama.
But the IUF's coordinator for Agriculture and Plantation, Sue Longley, told Radio Australia's Pacific Beat Commodore Bainimarama's appointment would legitimise a military dictatorship.
"We're concerned that his is having a dictatorship,a military dictatorship in Fiji, and during his regime, we've seen substantial erosion of trade unions and human rights in Fiji," she said.
"These have been well documented and recognised by the EU, by the organisations of Pacific States, by the International Labor Organisation."
The International Sugar Organization is an intergovernmental organization which seeks to promote the trade in and consumption of sugar.
Fiji produces two million tonnes of cane a year, most of it still cut by hand.
Ms Longley says the governments involved have criticised Fiji in other forums, and what it is calling for is a consistent approach.
"The ISO itself has a commitment...that its member must respect fair labour standards,
"We feel very strongly that Fiji is in breach of this agreement and certainly should not be received the chairmanship...it gives the regime a legitimacy we don't think it deserves."