The popularity of controversial Buy One Get Two Free deals continues to grow apace, with Tesco running seven times as many bogtf offers this year than in 2009.

Although the bogtf ­mechanic still accounts for only a small proportion of deals overall 259 out of a total of 97,123 the number has gone up almost four-fold over the past year, reveals the latest Assosia data. In the 11 months to 30 November 2009 the mechanic accounted for just 68 deals.

Conversely, the number of classic bogof deals has slumped 23% across the leading six supermarkets with 6,432 deals, compared with 8,308 last year.

The data also revealed that although Morrisons remains the number one retailer for bogtf, Tesco is catching up, with 66 bogtf deals in the 11 months to 30 November, compared with eight in 2009.

As with all retailers, most Tesco bogtf deals were on groceries, followed by ­impulse, health, beauty and baby.

The growth in bogtf comes despite mounting criticism that multibuy deals contribute to food waste. Last year, Defra called on supermarkets to put a stop to bogofs.

This year, the only supermarket to increase its number of bogofs was The Co-operative Group, which ran 1,032 deals compared with 947 in 2009. Asda has not run any bogof deals since last year.