This will be an interesting debate. The Rae days that the Conservatives and the unions railed against in Ontario are now the model (with no credit given) for the austerity policy of the Sask. government.
The argument is that it is temporary and prevents the alternative layoffs.
We have heard this before.
http://www.cbc.ca/news/canada/saskatchewan/sask-government-unpaid-leave-...
The policy was very unpopular here -- in part becuase of the way it was imposed. However, if you are making cuts it can be argued that it is a better way to do it. And I never did disagree with the mechanism. Unions as well have agreed to other kinds of job sharing arrangments to avoid cuts.
There were two problems back then and the same two apply now.
First is this austerity necessary and helpful? This is not a moral question, it is common that the employer has to prove cuts are unavoidable in order to make them -- and that includes paid hours.
Second, this is an alternative to layoffs which the employer may have a right to do but this alternative ought to be negotiated. The method of just legislating it is a violation of collective agreements. Ultimately the government can only negotiate such arrangements for them to be legitimate.
It is these two tests that decide if it is reasonable: Proof it is necessary and a negotiation.
It does not look like Saskatchewan has met either.