Thousands of Argentine farmers resumed a crippling strike on Wednesday after one month of talks with the government to roll back a stiff tax hike on soybean exports broke down, a union leader said.

Mario Llambias said the country's four major farming groups would stop all cereal exports in the country for one week and block the country's main roads again, although this time without stopping food supplies to major cities.

Angry over President Cristina Kirchner's tax on soybeans — Argentina's main export — farmers in March went on a three-week strike that emptied supermarket shelves of food in Buenos Aires and other main cities.

The strike presented Kirchner with her biggest test since she took over from her husband and predecessor Nestor Kirchner in December, and triggered a political crisis that cost Economy Minister Martin Lousteau his job.

A truce was called on 2 April to allow for negotiations that broke off on Wednesday with no agreement.

Before Llambias's announcement, Kirchner's chief of staff and top negotiator in the talks, Alberto Fernandez, warned farmers publicly: "if you go on strike, you'll have to deal with the consequences."

Fernandez said the government was "always open to dialogue, but will not tolerate the threat of a strike if they don't get their way."

The raising of export tariffs on soybean products from 33 to 44.1 percent is challenged by farmers, who claim that along with income taxes, transport costs and the high cost of land, it will push many of out of business.

The confrontation has deepened divisions between Argentina's upper and middle classes — including many well-off farmers — and the poor class, swollen by the country's 2001 financial collapse, which supports Kirchner.

AFP