http://www.royalmint.com/aboutus/news/g ... -reduction
Looks to be the way that coinage from the Royal mint will be produced.
"The Royal Mint’s license free aRMour® plating technology which replaces expensive solid alloy coins with a mild steel core electroplated with either nickel, brass or copper. This single layer or mono plate of typically 25 microns allows for a lifetime in circulation in excess of 20 years. In contrast, multi-layer plating has a thin outer layer of only 6 to 9 microns that can wear through in as little as five years in circulation, exposing the underlying copper layer."
So by my estimation, a 5.5% nickel plating might become standard (2% might be too thin) for the fifty countries in the commonwealth.