Mac users can't enter an online GMTV competition to win iBooks.

The breakfast ITV show is hosting a competition that gives viewers the chance to get their mitts on five of Apple's latest iBook laptops every day this week.

However, clicking the enter button to launch the competition triggers a message saying "your entry has not been received", and a note on the site says: "Entries are only valid from a home PC (not a Mac), using Microsoft Internet Explorer."

It is possible to enter the competition by telephone. Calls cost 60 pence per minute. The lines are open daily from 07:20am to 4:00pm and winners are announced the following day.

Designed by Jonathan Ive, the all-white iBook weighs 2.2kg and measures 28.5cm wide, has a depth of 23cm and thickness of 3.4cm. Prices start at £1,299 - the iBook is available in three configurations.