The only airline pax handlers are Ba, who may not be in man for very long, Bmi, mytravel, and sas, but as blue said, they also do checkin for other airlines, including PIA.
Jet2 are checked in by menzies, Emirates - Swissport, Etihad is also swissport but they have to wear etihad uniforms.
There are also another checkin compamy, Manchester Handling, checking in flyglobespan, euromanx, flyjet, airclass not sure if they do anymore as yet, but they may start recuirting in Dec, keep an eye on plane talk.