The promotion by the supermarket, which has included products such as Kintyre Breaded Scampi, Tilda Rice and Sugar Puffs, marks a U-turn in strategy. Tesco had previously launched a "buy one, get one free later" initiative, designed to encourage sustainable purchasing.
The apparent strategy shift has therefore raised eyebrows among both environmental campaigners and suppliers, who claim that promotions in this vein incur significant losses for suppliers and are bad for the environment.
Helen Rimmer, a food campaigner for Friends of the Earth, argued that such promotional activity encourages food waste. She said: "If Tesco is serious about the environment, it should ditch these cheap promotions."
Tesco last week confirmed it would be lead sponsor of next year's Climate Week, designed to raise awareness of climate change and promote ways to reduce global warming. The retailer has pledged to become carbon-neutral by 2050.
The supermarket is not the first to embrace buy one, get two free promotions: both Sainsbury's and Morrisons have also adopted the strategy.
Tesco was unavailable for comment at the time of going to press.