Very cheap deals available from Old English Inns (part of Greene King). We have stayed with them numerous times at different hotels and have always found them to be excellent. They also have good seasonal deals. I'd always presumed everyone knew about these but maybe not?
I've been lurking on HUKD for months and saved loads so I though I'd better post (finally!) I've had to put start and end dates but in my experience these deals are always available (but have to be booked just before travel in the case of the weekend deals). The seasonal deals can be booked quite a way ahead. Price is per night per person at the cheapest hotel though other prices are not much higher. To see these rates enter late_int as the promotional code.