Something’s been puzzling us recently. So far as we can tell, every political party in Scotland now supports the transfer of more powers to the Scottish Parliament. The SNP clearly does, but all of the opposition parties are also now insisting that they want to improve the devolved settlement over and above the limp Scotland Bill currently staggering its way through Westminster.

We know the Lib Dems in both Holyrood and Westminster are in favour of more powers, because no less a figure than the Scottish Secretary told us so:

We had confirmation yesterday that Labour in the UK (along with Scottish Labour) also want more than the status quo, in the words of Alastair Darling:

And of course, for the Tories, the Prime Minister himself has made his position clear (albeit that he had to humiliate the leader of the Scottish Conservatives to do it):

So that’s all just grand. We have that rarest of political beasts, a true cross-party consensus: everyone (except poor Ruth Davidson, who we suspect is in the process of urgently revising her opinion) agrees that the Scottish Government should have more powers. But what we don’t understand is why these powers are all conditional on a No vote in the independence referendum.

Because for some reason, all three Unionist parties are agreed that Scotland can only have these powers AFTER it votes against independence in 2014. Why? If Scotland should have more powers, Scotland should have more powers. The Scotland Bill is still at a stage where it can be amended before passing into law. Why doesn’t everyone just sit down one afternoon, find out which powers they all agree on, and add them to the Bill now, rather than laboriously repeating the entire legislative process from scratch in three years’ time?

All three opposition parties are demanding the Scottish people trust them, despite every one of them having a track record of broken promises. The Tories have previous for doing this exact thing – promising better Scottish devolution in the event of a No vote, only to go back on their word. Labour, of course, infamously scuppered the first devolution referendum by counting the dead as No votes. And by his own frank and open admission, the very same Scottish Secretary quoted at the top of this piece is a known liar when it comes to political pledges.

What the Unionist camp proposes, in other words, is a bit like a Mexican stand-off in which one side says “Okay, if you put down your gun first, I’ll consider whether or not I’m going to shoot you. Oh, and bear in mind, I have a habit of shooting people when they put their gun down.”

If the Unionist parties are sincere in their desire to give Scotland more powers, let them demonstrate that sincerity by getting on with the business of improving devolution properly now, not at some unspecified point in the future.

There are already half-a-dozen proposals for amendments to the Scotland Bill on the table from the Scottish Governent, none of them enormously dramatic and all of them backed by at least one of the opposition parties. Westminster could easily show good faith by adding some or all of them to the Bill as a starting point, and the coalition could sit down with Labour to discuss what other common ground they might have on the matter, and make a statement about it long before autumn 2014. (As we write this it is, after all, still only early 2012. It can’t take terribly long, surely, to sit round a table and go “Excise duties, yes or no?”)

Such a unified commitment from the three parties would also serve to reassure the Scottish people that greater devolution was safeguarded no matter which of them won the UK General Election in 2015. Yet we’re told, without a reason being given, that such discussions simply can’t take place until after Scotland gives up its only bargaining chip for a generation. That’s not a Mexican standoff, it’s the end of “Butch Cassidy And The Sundance Kid”.

It’s taken 300 years for the Scottish people to win itself that bargaining chip, against relentless opposition, obstruction and trickery from the same people who are now asking us to innocently trust them. We doubt Scots will be so easily fooled this time.