In the meantime assuming yours is a wooden stock - use araldite or some other good epoxy glue to glue the two parts back together - then further strengthen with either a long screw or piece or metal rod drilled from inside the action back down into the pistol grip. Should keep you going for a while until you get a new stock.
Try Staffordshire Synthetics (do a search on google). They will advised you accordingly. They have excellent quality stocks ready for drop in. Should set you back about £200 - 250 and they are as good as McMillans in terms of quality.
The alternative from the US is a Boyds laminate or the others ie McMillan at approx £400 etc