As for whether other unions can cash in on the PSA's agreement, Weatherhead notes, it was only a few years ago that the PSA did the same thing, and was able to secure an adjustment to previously-settled negotiations. Still, he says, that does not mean there is a precedent.

Weatherhead agrees however, that for those who are yet to settle for 2014 to 2019, there is a reasonable case to bargain at 10%.