According to recent reports , David Cameron is again exploring the possibility of staging a pre-emptive, Westminster-led referendum on Scotland's secession from the United Kingdom. At the same time, one of the country's leading authorities on the British constitution, Professor Adam Tomkins of Glasgow University, has claimed  that the Scottish Parliament does not have the "legal competence" to hold a vote of its own, and that the UK government should call one "as expeditiously as possible".
The developments will be welcomed by the most zealous opponents of independence. Hardened Unionists like Lord George Foulkes and Tom Harris MP, currently a candidate in the race to be the next leader of the Scottish Labour Party, have been arguing since May that London should assume control of the referendum process in order to prevent the nationalists from "rigging" it in their favour.
Events over the last couple of weeks may have encouraged other, more moderate Unionists to move toward this position, too. Alex Salmond's assertion that any kind of majority for full Scottish sovereignty would be binding - even if in a two or three option ballot it is delivered alongside a larger majority for, say, full fiscal autonomy - has re-enforced the No camp's suspicion that the SNP cannot be trusted to play fair when it comes to Scotland's constitutional future.
But can anyone? The Unionist parties accuse the Scottish government of being incapable of running an impartial ballot because it has an interest in the outcome. Yet there is no reason to believe the UK government - which, of course, also has an interest in the outcome - would be any more objective in determining the timing of the vote or the wording of the question. London's track record on the management of Scottish elections provides little reassurance. In 1979, Jim Callaghan's Labour administration manipulated the first devolution referendum by packing it with legislative provisions - like the infamous 40 per cent rule - designed to secure its preferred result.
Another, equally limp, Unionist complaint is that the SNP won't let the Electoral Commission (EC) oversee the voting procedure. Well, why should it? The last time the EC directly ran a Scottish election - in 2007 - it caused an unholy mess, with as many as 140,000 votes eventually discarded . At any rate, the question of impartiality has already been addressed by the Scottish Government. In its Draft Referendum Consultation Paper published last year, it pledged to establish a Scottish Referendum Commission  to regulate both the campaign and the ballot. This Commission would, "with limited exceptions, be completely independent of the Scottish Parliament and Government in the conduct of its affairs".
Then there's the endlessly discussed matter of "mandates" - who has one and who doesn't? Tom Harris insists that the SNP, having campaigned on a platform to break-up Britain and not to turn it into a federation, has no mandate  for a referendum on anything other than straight-forward independence. Perhaps he has a point. But then the rule works both ways. Neither Labour, the Conservatives nor the Liberal Democrats campaigned for an independence referendum in 2010 or in 2011 (or ever), so by Harris's logic none has any democratic right to hold one.
The UK parties also need to consider the likely political consequence of hijacking Scotland's referendum. Does Scottish Labour, which is in the process of trying to develop a more distinct Scottish identity, really want to be seen to be colluding with a hugely unpopular Conservative-led government to undermine the clear choice of the Scottish people? Do the Liberal Democrats - already a federalist party - want to risk full oblivion for the sake of a crumbling Union?
The personal credibility of the Prime Minister and the Secretary of State for Scotland are at stake, too. Both David Cameron  ("The SNP has won the right to hold an independence referendum") and Michael Moore  ("I firmly believe the Scottish Parliament, if it so decides, can proceed with a referendum") have stated at different times over the course of the last seven months that Holyrood is in the driving seat on this issue. This weekend, George Osborne also appeared to agree  that the "ball is in [Salmond's] court". A sudden, coordinated u-turn would look like - and in fact be - an act of breathtaking cynicism.
In the coming months, the Scottish government is going to bring forward a motion at Holyrood which invites MSPs from across the chamber to affirm the "democratic authority" of the Scottish people. This 'Claim of Right ' - first agreed on a cross-party basis in 1988 - will assert unambiguously that ordinary Scots should determine "the form of government best suited to their needs". Legally, of course, the motion will be worthless: Edinburgh doesn't have the power the challenge Westminster's sovereignty. But it is a typically astute piece of political manoeuvring from the First Minister. When it comes to a referendum on Scottish self-government, it seems, the people have the SNP's backing and the SNP can say with some confidence that it has the people's.