But a change in the British constitution would require a UK-wide referendum, too. A third may be required to ratify the negotiated settlement, which could turn out to be significantly different from popular preconception. Assuming the answer to all of these is "Yes", a further referendum may then be required on whether an independent Scotland should apply for membership of the EU, from which most legislation now emanates anyway, taking the final tally to four.
The prospect of a chain-reaction series of referendum votes - starting with a vote only to authorise the parliament to enter into negotiations on separation - may seem bizarre. And by the time the process is finished, the public may have grown heartily weary of the prolonged uncertainty. But there are issues here of democratic legitimacy and the need for Scotland to be sure that if constitutional change is undertaken, it should be the considered and settled will of the Scottish people, not a random walk through the ever-changing, "will-o'-the-wisp" mood swings of the political anorak set.
Debate on the "chain reaction" road to independence was effectively kick-started by a welcome weekend clarification by SNP leader Alex Salmond that his party, if elected, would plan to call a vote on independence by 2010. This at least lightens some of the fog that had descended following remarks by party donor Sir Tom Farmer that the party might not pursue a vote on independence and needed time to prove itself.
But no sooner has one mist lifted than others have rolled in. Constitutional experts point out that, because of the limited powers of the Scottish Parliament, the referendum will only be able to ask the Scottish people if they are willing to begin negotiations on independence - rather than a straight question on whether they are in favour. This, it is envisaged, would lead to the UK government, as guardian of the constitution, calling a further referendum on whether the UK should undergo a break-up.
All this would suggest that independence would not be a sudden event, but a process, and one that could take more than four years to complete, requiring the SNP to win a second election. According to John Curtice, professor of politics at Strathclyde University, even if Scotland votes in favour of initiating negotiations, time must be allowed for these negotiations to take place, followed by a possible second UK-wide referendum on whether to go ahead with the break. However frustrating this may be for the independence "fundies", this cannot be settled by blind rush.