WAITROSE has attracted ridicule on social media for selling empty jam jars for £2 – 29p more than the cost of a full one.

Waitrose shopper John Kilbride, from Glasgow, noticed that a store was simultaneously selling the luxury Bonne Maman conserve for £1.71 and an empty jar for £2 and put pictures of them on Twitter in a post that has been liked more than 5,000 times.

He wrote: “At Waitrose you can buy an empty jam jar for £2 or an identical one full of jam for £1.71. You decide...”

Some consumers defended the grocer, pointing out that the Bonne Maman was on temporary offer and the empty jar was bigger, despite their near-identical appearance complete with red gingham-patterned lids.

Others, however, suggested that the supermarket was clearly targeting “middle-class jam makers” and joked that it was clearly the “preserve of the wealthy”. Some shoppers commented that the product should be re-labelled as “Waitrose Bottled Fresh Air”.

A Waitrose spokeswoman said: “Our Bonne Maman conserves are on a temporary promotion and are great value for money.”

The Women’s Institute advises that sterilising jars for home-made jam simply requires washing them in very hot, soapy water, rinsing well and placing them on a baking tray in the oven to dry completely. Last year analysts Kantar Worldpanel reported a resurgence in packed lunches, with 25 to 35-year-olds the most likely to swap bread-based meals for lighter, healthier options.