I can't talk for that far up north, but at MAN...
Average Swissport loader is between £7.00-£7.80 flat rate.
Average Servisair loader is between £8.00-£9.00 flat rate.
Difference being Servisair staff get various extra payments, shift pay, night pay, sick pay etc etc, Swissport staff get a flat rate regardless of hours worked.
Someone worked it out and worked out about 20% less a year at swissport