The Chancellor was following in the footsteps of those campaigning against Quebec's sovereignty when he made his pound gambit this year. They, too, had railed against currency union during their 1995 campaign to keep Quebec in Canada. But it is far from clear that the threat, as it was seen, had a big impact in the Canadian province.
Donald Turp believes a counter-threat worked. The Parti Quebecois strategist and speechwriter at the time of the 1995 referendum said: "We wanted to be independent but we also wanted a partnership with Canada, and wanted to maintain this economic and even political union … But the No side said, 'It's not sure you can use the Canadian dollar'.
"Then Jacques Parizeau, the PQ leader, said something like, 'Do you know how many billion of dollars Quebecers have in their pocketbooks, their bank account, their socks, in their mattresses? … If Canada doesn't want us to use the currency, we'll just tell Quebecers to buy American dollars.' The No side didn't talk much about the currency after that."
Earlier this year, another Canadian, Bank of England governor Mark Carney, spelled out just how much sovereignty Scotland would have to cede over fiscal policy to keep a currency union. Canadian federalists suggested his argument struck a blow at "the idea that an independent Quebec would have all the tools to manage its economy".