The price hikes are a result of Virgin Mobile scrapping a number of older tariffs and moving customers onto the closest equivalent tariff available – some of which will be more expensive.

Virgin Media, which runs Virgin Mobile, would not confirm which tariffs are affected. It said it would be contacting customers directly.

Customers can switch to another Virgin plan or leave the provider altogether penalty-free. However, they must inform Virgin by 31 March 2020 if they wish to do so.

Virgin said the “vast majority” of customers who will see bills rise will receive an increase in airtime allowances.

A Virgin Media spokesperson said: “We’re updating some of our older mobile plans so that our customers can continue to enjoy the best of our services. As always, any changes made will be communicated to our customers in a clear and timely way.”