Further to my last post and to bring the thread back to the top:
Personal Computer World arrived today and had the Tiscali disk with it. IE 6 is on the disk in its entirety (70MB).
The BT disk has it as well (48MB).
OneTel doesn't have IE6.
FreeServe just give you a link for an installation from the Web.
Tiscali seem to be the best bet but watch out for "Branding". That is, even if you don't sign up to Tiscali your Brower and Outlook Express may have "Tiscali" in the Title Bar at the top.
You may avoid this if you install direct from the Setup.exe in the Folder on the CD instead of through the Autorun Menu.