A week after students called for a boycott of Tnuva products, sales of the fresh-foods company's dairy products have continued to decline, despite aggressive discounts. Heightened demand for products made by competing companies Strauss and Tara has caused shortages at some points of sale.

On Tuesday, a group of students will be holding a protest outside Tnuva headquarters.

The boycott declared last week is another stage in the social protest that began with a boycott of humble cottage cheese, after its price rose to about NIS 7.50 per container. A Facebook protest morphed into a huge public outcry, following which the dairy companies lowered the price to consumers to NIS 5.90.

Tnuva has fought back against last week's boycott with aggressive discounts, including an offer of two tubs of cottage cheese or soft white cheese for NIS 10, in containers that hold a free extra 10% or 20% of the cheese. Tnuva is also offering 50% off the second product for a wide range of products. Tara, by the way, is also offering bigger containers of some products for no extra money.

A top executive at one marketing chain says sales of Tnuva products were down 2.5% Monday compared with pre-boycott levels. Sales of rival dairy company Tara were up 9%, he said. Sales of Strauss products were up a more modest 3%, he added.

Another chain shrugged off the boycott, saying Tnuva sales were unchanged - an indication of the equilibrium between the boycott and its aggressive discounts, which would otherwise have been expected to increase sales.