Retail resistance is building to intentions by mobile phone service provider T-Mobile to reduce margins on e-top-up transactions.

The company has confirmed plans to cut commission margins on Pay as You Go by 0.5%.

One of The Grocer's Top 50 independent retailers said: "I understand that it is T-Mobile's intention to reduce retailer commission on top-ups. Any cuts in commission rates will damage thousands of independent retailers. I further believe that T-Mobile is on target to make substantial profits this year. I would like to know how cuts to retailers can be justified."

Many shoppers top up Pay as You Go cards using PayPoint or Payzone terminals and T-Mobile's plans would hit all those transactions. It is understood that Spar is in heated discussions with T-Mobile. Nisa-Today's has also been pressing for an explanation.