Cheap, throwaway fashions account for up to 30% of the waste at some landfill sites, a committee of MPs says, with what they describe as the so-called "Primark effect" raising concerns about sustainability issues.

Speaking last week at an inquiry by the Environment, Food and Rural Affairs Committee into England's waste strategy, MP Michael Jack said some council tips had seen the amount of textile waste rise from 7% to 30% over the last five years.

This, he said, presents real challenges because cheap fashions are often made from man-made materials that cannot easily be recycled, and the only disposal options are "landfill or burning them."

He added that workers at one waste-disposal site in Croydon called this the "Primark effect" after the popular budget clothing chain that sells fashion at rock-bottom prices.

Julian Walker-Palin, head of corporate policy for sustainability and ethics at UK supermarket group Asda, was also at the hearing.

He said the retailer is moving away from impulse buys, "which fast fashion tends to be" and focusing instead on wardrobe essentials in response to demand from customers.

 He added that shoppers "are making product choice decisions now around quality and value for money," and Asda "has now completely changed our brand offer on our George clothing to reflect that and are moving away from the so-called fast fashion."

The retailer has brought in three new brands - Moda, Boston Crew and G21 - reduced its clothing options by 20%, and is now focusing on styles "which will last for a considerable period of time."

Michael Jack, who chairs the committee, said he was still concerned that cheap clothing seems to take up an increasing proportion of the waste stream "with difficulties for ultimate disposal and so some quite serious questions on sustainability."