Stores across the UK are stocking all-white packets of Skittles in support of the annual LGBT+ festival, which gets underway this weekend.
Colin Hart, Director of The Christian Institute, claimed Tesco has gone "out of its way" to back the lesbian, gay, bisexual and transgender agenda.
He said: "Why does any kind of sweets need to be politicised? People should be able to buy their favourite confectionery without being forced to consume a political message as well."
Marketed under the slogan 'Taste the Rainbow', packets of Skittles usually include small circular sweets in a range of colours.
Skittles unveiled the new all-white packs, saying: "During Pride, only one rainbow matters. So we've given ours up to show support". The rainbow has long been associated with the gay rights movement.
Proceeds from each packet - which will be available until September this year - will be given to LGBT groups selected by Tesco.
Asked for a response to the Christian Institute's comments, a Tesco spokesperson told Premier: "As a proud sponsor of London Pride we are offering our customers Pride themed products, including special packs of Skittles."