Pretty straightforward really...
Travelodge currently have a £19 promo on over the May holidays.
For some reason for the week following Sun 24th April you can find plenty of £15 rooms!
Obviously book em quick before they're snapped up, or the date ticks over, as you know Travelodge require booking in advance for these saver rates ;)
Check it out!!!
NOTE: Please see: http://www.hotukdeals.com/deals/15-room-sale-starts-7th-april-travelodge/913990
this deal has already been reported, but I couldn't see it at the time.