What forced Scotland to the top of the agenda was the growing popularity of the Scottish National Party and its support for outright independence. The SNP had proved Labour’s prediction that “devolution will kill nationalism stone dead” to be completely wrong. By May 2011 it was heading into a Scottish parliament election with a manifesto commitment to an independence referendum. If it won a majority, it would claim a democratic mandate to hold one.

Many people wanted to make a referendum non-binding or to deny it altogether. After all, a referendum would be a massive gamble. The Union we loved could be broken in two. Some would do anything to avoid that — or, more realistically, to put it off until another prime minister’s watch.