Quechua Base Seconds Tent - £54.99 @ Decathlon
Quite a good reduction on these tents, they are usually at least £90.
I bought one of these for Glastonbury and have been waiting for the price to come down for a while. They are really highly rated pop-up tents so would be great for the summer.
Previously posted at £64.95 here: http://www.hotukdeals.com/item/624435/quechua-seconds-base-utility-tent-6
Note that you'll need a ground sheet (£10) and bedroom (£30) section ideally to sleep in one of these.