Consumer groups and hundreds of supermarkets in Argentina are launching a tomato boycott to protest against what they say are rising prices.
Consumer groups say basic goods prices have risen sharply
The groups have challenged official inflation figures, saying these are out of sync with market prices.
Argentine President Nestor Kirchner has defended official data that put inflation at just 0.8% in September.
Inflation has become one of the main issues in Argentina's presidential elections later this month.
Mr Kirchner's wife, Cristina Fernandez, is the current favourite to win the 28 October vote.
Organisers of the tomato boycott say official statistics list tomatoes at 3.99 pesos ($1.3) a kilo, but vendors are selling the vegetable at up to 18 pesos ($5.8), putting it out of the reach of many Argentines.
They are calling for the government to guarantee the officially listed price during the week-long protest.
Mr Kirchner is credited with bringing Argentina back from the brink of economic collapse since he came to office.
But in some parts of the country poverty is still widespread.
Ms Fernandez has promised jobs and economic security if elected.