Was at the Marks & Spencer Outlet in Glasshoughton (Castleford, nr Leeds) today and they had dozens of maternity bras reduced to £1 in their clearance section (not with the normal undies). The majority of them were in size 34D, but there were a few others. They were plain white, looked like quite good support, non-wired.
The M&S Outlet at Doncaster Lakeside also had loads of the same style last week for £2.50 so I'm guessing that they've got them nationwide and they've been further reduced. Donny also had, if I remember correctly, mainly 34D as well with a few 34DDs that I noticed.
I know this is quite specific, but anyone who is pregnant will agree that this is a real bargain - these things cost an absolute fortune normally!
I resisted the temptation to buy the lot and Fleabay them...suppose there'll be someone else just behind me though!
You can find your nearest Outlet store from the link here - select 'Outlet Stores' from the drop down menu. http://www.marksandspencer.com/gp/store-locator/store-locator.html