Well it is not so easy. First, they will need to modify the constitution, which requires being approved a qualified majority not a simple one in parliament, in this case, is 3/5 of the parliament this reform might need to be approved by referendum (all the country not just Catalunya) in case a tenth of the parliament requires it. Second, the government has no desire to modify the current regional system, which is in line with its voters. Anyway the Canada case is not the norm and similar legislation are in use in other countries, for instance in Germany. https://www.thelocal.de/20170103/bavaria-must-remain-part-of...