Fashion chain New Look is reviewing its prices after a shopper found that some plus-sized clothes were more expensive than identical styles in smaller sizes.

The retailer said it was “reviewing the pricing structure” of its plus-size collection in a way which “works best for our customers and our business” after shopper Maria Wassell spotted that trousers in its Curves range cost 15% more than a pair in the main collection.

Ms Wassell’s observation has led to some suggesting it is reasonable for retailers to charge more for a garment that uses more material, while others have described it as a “fat tax”.

Ms Wassell, a retail supervisor from Kent, told the Sun newspaper: “It’s like I’m being discriminated against for being plus-size when I’m only slightly bigger than average.

“The average size for a British woman is now a size 16. Plus-size purchases are on the increase. If you look at the statistics, there’s more money being spent on plus-size clothing now then there was even three years ago.”

Ms Wassell said she used to work for a plus-size brand, and described the suggestion that clothes for bigger sizes needed to be more expensive was “basically rubbish”.

New Look said in a statement: “We are in the process of reviewing the pricing structure of our plus-size collection in a way which works best for our customers and our business.

“We are proud of the ranges we offer to our plus-size customers and value all customers, no matter what their body shape or size.”