Flights
Below is a list of flight operators with links to their websites. For the best deal, you can always go with one operator to ,say, Alicante & return via Murcia with another. Wegolo will search all the following sites (& hundreds more) & save you the hassle of doing it yourself. It's good because you can book outward & return flights with different operators but using just the one site. I think there is a small fee of £12.00 to pay for this.
From Manchester
Monarch ~ Alicante
Air 2000 ~ Alicante
BMI Baby ~ Alicante
Thomson ~ Alicante
Jet2.com ~ Alicante & Murcia
From Liverpool
Easyjet ~ Alicante
Ryan Air ~ Murcia