Sports Direct, Britain's biggest sportswear retailer, has responded to criticism of staff practices by launching a review of its agency workers' terms and conditions which will be overseen by founder and deputy chairman Mike Ashley.

The FTSE 100 company has been in the spotlight after The Guardian newspaper reported last week that lengthy and unpaid security checks of staff at its main warehouse in Shirebrook, central England, meant that some workers effectively earned less than legal levels.

On Monday, Sports Direct was criticised by lawmakers in parliament and a government minister said it would face sanctions if it flouted wage laws. “The board has agreed that Mike Ashley shall personally oversee a review of all agency worker terms and conditions to ensure the company does not just meet its legal obligations, but also provides a good environment for the entire workforce,” the company said.

Mr Ashley will start work on the review next month. Sports Direct also hit back at some of what it called “unfounded criticisms” it has received. “Various parties have chosen to ignore the facts provided and have continued to present an unfair portrayal of the company’s employment practices,” it said.

Sports Direct shares, down 17 per cent over the last month, were down 0.3 per cent at 574.3 pence today.