Griffo,
Thanks for the implications on a personal level, going back a wee bit further I believe it was ATC (rightly or wrongly) that brought in the 17% leave loading whilst on holidays.
That is when we went on leave we lost the shift penalties because we weren't working shifts. It was argued that we actually took a paycut when we had holidays and our pay was less than when we were actually at work. The IRC of the time agreed and gave us a 17% leave loading, in the days of rabid unionism others dived on board, and it ended up that most ended up with it, even if they didn't work shift work. Go figure?
As far as I was concerned it had nothing to do with sick leave, but all to do with looking after experienced, committed people who were taking a paycut to do what people who are now getting grossly inflated wages are doing.