Labour’s motion on the referendum being debated as I type is pretty thin gruel:

Johann Lamont: Scotland’s Future—That the Parliament recognises that the Scottish Government has a mandate to call a referendum on the constitutional future of Scotland and calls on the First Minister to hold immediate cross-party talks, including with leaders from all quarters of civic Scotland, to agree a timetable for the referendum, to ensure that the referendum provides a clear result on a single question and to ensure that the referendum is run in Scotland by the Electoral Commission so that the people of Scotland can have an early and rigorous debate on the future of Scotland.

It must again cheer SNP hearts to see the Scottish Labour Party sign up to chunks of the UK administration’s misguided intervention, and the call for cross-party talks on the timetable only will easily be brushed off by the Maximum Eck. A call for an open constitutional convention to involve the public and civic Scotland in the broadest sense would have been more constructive, notably if it was to consider what kind of independent Scotland the public wish to be offered, in constitutional terms, and whether there is indeed real public demand for devo max. But that call remains something only the Greens are making so far, unfortunately.

The “single question” aspect is the most critical part, though. This is perhaps the only part of the phoney war over process that Labour could have influence over. A clear and robust decision by Scottish Labour to set out a devo max option (or full fiscal autonomy, or indeed anything more coherent than the Scotland Bill) would surely have seen the SNP bring that forward in legislation. The Nats have issued enough press releases trying to provoke Labour into doing precisely that, and Ministers have essentially committed to offering the middle way if someone else comes up with it.

Why have Labour turned this offer down? Let us assume it’s tactical rather than some reference to party policy.

Lallands Peat Worrier has made a comprehensive and convincing case that a devo max option would reduce the chances of an independence victory. So if Labour were looking to minimise the risk of Scotland going it alone, surely they’d have set out some middle position, even if it didn’t go as far as devo max? Mere devo-plus would have sufficed. More powers is a form of pragmatic Unionism in the same way Holyrood itself was Unionist – an effort to head off independence at the pass.

Although the poll results showing support for devo max may largely be driven by people tending to pick the middle option, as LPW says, there would have been major media and political advantages to Labour if they had been the party to set out what that middle option would have been. They’d have owned a question on the ballot, they could have been virtually centre stage throughout the debate, they’d have had something positive to make the case for, and their option would have been quite likely to have won.

But devo max is also what would suit a personally ambitious set of SNP Ministers best. As I’ve argued here before, it gives them a moderate win, a step towards the holy grail, something to keep the activists happy, yet it also allows them to keep governing. It’s almost impossible to imagine an SNP devo-plus administration not being returned in 2016. Declining the offer to set out an extension to Holyrood’s powers suggests Labour are more afraid of seeing the SNP’s hegemony grow and strengthen than they are of an increased risk of full independence.

A Yes vote, however, would see the SNP achieve their only purpose while would also depriving them of it. It would make the contest for the first post-indy Scottish Government an open one, one which Labour no doubt feel in their secret heart of hearts that they would well placed to win. The constitutional question would for the first time (deep intake of breath) not overshadow the other issues politics urgently needs to deal with – poverty, public services, taxation, climate change, the rest. Indeed, one former very senior Labour figure once told a friend of mine they’d be fine with independence so long as the Nats weren’t running the show.

Conversely, an outright No vote sends the SNP activists back home in despair and puts the question on hold for a generation – unless the SNP didn’t notice what happened to the Bloc Québécois when they kept pushing it. There is no burning agenda for the SNP to deliver with the existing powers, we know that already, just some pretty right-wing tax proposals for an independent Scotland, and so again a No vote could well be followed by a Labour-led administration on the existing powers. A stronger prospect of returning to power at Holyrood looks more important to Labour than reducing the risk to the Union, whatever they say in public.

Devo max may be Unionism, but few on that side of the argument would be so foolish to regard it as likely to kill nationalism stone dead. In fact, if you want to kill nationalism stone dead there’s only one way to do it. Give it what it’s always said it wants: a clear yes or no on independence. Conveniently, that’s also the best sort of ballot paper for those of us who want independence but also want to see the back of this economically right-wing SNP administration.