I would have thought that if the unions came out and said something akin to "we'll help cut the public service pay bill........we'll support cutting public sector numbers by e.g. 10%......and the remaining employees will agree to redeployments and taking on the workload of the 10% who leave...etc. etc." then they would be taken seriously as, to be honest, cutting surplus staff in programme areas that have their funding (workload) reduced is the best way to cut the public sector pay bill
I don't think that would look too good. Sacrifice 10% so that 90% continue to enjoy their current level ofl wages?