I believe they're on the sky pick channel which may be outside of any subscription package
They are on Sky Pick, and on SkyOne. (not SkySportsOne, SkyOne the entertainment channel)
This is an important piece of information that always gets committed as SkyOne means if you have NowTV or other streaming packages that is generally included.
And secondly, SkyOne is available in HD. Whereas Sky Pick is not.
But Sky Pick is a free TV channel on Freeview, Freesat and Virgin. The only problem is, the Picture quality is not as good (for me at least) as what you get on the major channels. Hence why SkyOne on NowTV is a good workaround.