The release of Apple's second-generation iPhone 3G is just days away, and demand for the new device is already reaching frantic levels.

Exclusive UK provider O2 has announced that the iPhone 3G will go on general sale from 8.02am on 11 July and will be sold on a first come, first served basis.

"We have never seen any mobile device create the excitement and demand of the iPhone 3G," said Ronan Dunne, chief executive at O2 UK.

"We want to ensure that everyone who wants an iPhone 3G can get one, so we will be working with Apple to continually replenish our supplies throughout the summer."

Customers who had pre-registered an interest in the iPhone 3G were given the opportunity to purchase one of a limited number set aside at O2's online shop.

Once the gates were opened demand was so high that it crashed O2's site, but despite the technical problems stock was completely sold out in a few hours.

Business customers can start placing orders for the iPhone 3G through one of 16 O2 business channels.

Those hoping to snag one of the new phones on a pay-as-you-go basis are going to have to wait until Christmas, according to O2.