A lobby group for Kenya's organic farmers, Rodi, has welcomed a decision by the UK's Soil Association not to ban organic produce imported by air.
Much African produce has to be flown to Western markets
African farmers risked losing $66million (£32.6 million) in annual retail sales if the ban was imposed.
But other farmers in Kenya say new ethical trade standards that are also being imposed are "protectionist".
The International Trade Centre in Geneva also argues these will mean new costs for poor African farmers.
The Soil Association - the body that certifies UK organic produce - will require farmers to prove they provide employment at fair pay and that they are trying to lessen dependence on air travel.
The BBC's business reporter Mark Gregory says they can do this, for example, by developing local markets for organic produce.
However farmers' representatives say that in practice there is no real alternative to air freighting goods to where the demand is - among wealthy consumers in countries thousands of miles from where the products are grown.
Rodi's Esther Bett told the BBC the Kenyan farmers are happy that they will at least still able to export to markets in UK.
But a Kenyan oilseeds producer said he was not impressed by the new measures.
"I think it's a protectionist measure. Competitiveness is at stake here and therefore because a lot of produce is from the Third World the local farmers lobby is against it," Vimal Shah told the BBC.
African farmers want fair trade rules to open up markets
Britain's Trade and Development Minister Gareth Thomas said he was concerned for "the livelihoods of the African farmers who don't meet these extra standards".
Thousands of farmers in Kenya and Ghana depend on supplying fresh produce to European markets.
Airfreight, which some see as environmentally damaging because of the harmful emissions produced by flying, is the only way they can get perishable produce to these markets.
The International Trade Centre issued a statement saying the proposed changes would just add further costs to poor African farmers seeking to enter UK markets.
"Organic production in Africa has been an export success story and we are disappointed that the Soil Association will make it harder for African companies to enter lucrative markets," said Patricia Francis, ITC's Executive director.
The Soil Association's planned new measures will be put out to consultation next year, and it hopes they will be implemented from January 2009.