Mobile Today is reporting that 3 has been "caught out" by high levels of demand for its prepay Skypephone, with many stores selling out of handsets within days of its launch.

The device, which allow users to make free Skype calls in exchange for a minimum monthly top-up of £10, is just "flying off the shelves", according to 3 staff country-wide.

A central London 3 store has apparently said their initial allocation of 10 phones sold out and their next 25 due in are pre-sold, while a Newcastle branch had a similar tale to tell.

"Loads of people have walked in and asked what it's all about. I think it's the 'wow' factor when you explain it and tell them it's free", Mobile Today quotes a staff member as saying.

A spokesperson woman for 3 said demand was high but plenty of stock as heading to stores.