Customers who have a .co.uk domain registration have been emailed from Nominet to say the .uk is available exclusively to the .co.uk holder. As of 25th June the .uk domain will be available to the general public. This does not mean you will lose your .co.uk domain it only asks if you would like to purchase the .uk for your domain.
If you wish to purchase the .uk domain it will be £8.46 plus VAT every 2 years. Please send the request into email@example.com