The Plastic Bag Tax made some people very angry and confused, despite it being one of the most simple premises in the world. Either way, most people back the idea of reducing the amount of plastic bags used in England, and who can really complain if the money generated from the 5p sale goes to charity?

Well, it looks like Sainsbury's are employing a loophole and have been accused of giving less money to charity than their rivals.

So what's the craic? Well, most supermarkets are using the same plastic bags as before, and giving the proceeds from them to good causes. Sainsbury's however, have got rid of all their old plastic bags and have replaced them with sturdier, reusable bag for 5p, with free replacements when they break or wear thin.

The kicker here, is that these carrier bags fall outside the new law, which means that Sainsbury's have no obligation to give anything to charity.

In a statement to The Telegraph, Sainsbury's said that some of the money from the 5p charge goes toward the cost of supplying their new bags, which are pricier than the bog-standard carrier bags. They are voluntarily giving the rest of the money away to good causes. The rest of the supermarkets are offering bags that are less than 0.07mm thick, and are only allowed to take "reasonable costs" from the 5p fee. Asda and Morrisons waived their opportunity to deduct costs entirely. Official guidelines on the deductions a business can take are: "You can’t include existing costs, such as the cost of the bags. You’re likely to see reasonable costs significantly reduce after the first year."

And lo, it turns out Sainsbury's have been able to reduce their costs by this method, but the bags they're selling must also be sold for more than 5p by law, but they don't have to because they can reduce the price using the money they would've given to a charity. It is worth pointing out that they're not actually doing anything illegal, but there's going to be some consumers that aren't happy about this, and think the whole thing is not really in the spirit of scheme.