I very much doubt that it would be cheaper to get an 'on the day' ticket. Some 'full fare' airlines will let you haggle for a last-minute fares but most budget airlines charge the absolute maximum fare for a ticket purchased immediately prior to travel.
Here's a list of the operators providing scheduled flights out of Alicante to the relevant area of the UK:
To Manchester:
Jet2.com
ThomsonFly
BmiBaby
XL
Monarch
To Liverpool:
easyJet
Ryanair
To Leeds/Bradford:
Jet2.com
To Blackpool:
Jet2.com
Your post doesn't indicate when you want to travel but I assume that it's 'as soon as possible'. Jet2 are offering �125.99 per person (including taxes) into Leeds/Bradford for a night flight tomorrow. An afternoon flight costs �140.99 (inc taxes) p.p.
If you can wait until Monday, Ryanair will fly you to Liverpool (evening flight) for �132.99 (inc taxes) per person. easyJet can get you there tomorrow for �146.32 (night flight) or �151.66 (lunchtime) p.p., inc taxes.
XL will fly you to Manchester tomorrow (1045 flight) for �98.58 per per, including taxes
http://es.xl.com/
Those are the cheapest I can find for the immediate future but the other airlines might be cheaper on different dates.
Chris