The Cairns Group of free trading agricultural nations is seeking an early end to the use of export subsidies by the EU as part of a final deal under the Doha Development Round of world trade talks.

Last year, Brussels negotiators indicated they would be willing to phase out these subsidies – a key mechanism for bridging the gap between EU prices and lower world prices – though gave no clue as to the timescale.

 But at a meeting of Cairns Group ministers in Columbia this week, chairman Mark Vaile, the Australian trade minister, called for “an early end date for the elimination of export subsidies”.

 “The Cairns Group has long argued for equal treatment for agriculture, along with other sectors such as industrials and services which have seen significant liberalisation,” he said. “Farmers need markets that are not corrupted by the subsidies and protectionist practices of a few rich countries.”

Mr Vaile urged “leadership and flexibility” from EU farm commissioner Mariann Fischer Boel and US agriculture secretary Mike Johanns, who were both at the Columbia meeting, to secure a framework deal by December.

But the difficulties that lie ahead are considerable. A recent negotiating session in Geneva had to be suspended because of deep divisions about how to convert existing border tariffs into uniform “ad valorem” tariffs, based on a percentage of each product”s value.

 This was supposed to be wrapped up by the end of March, in order to present the figures to WTO members later this month. But that deadline appears to be slipping.