DURING the Boris Johnson premiership, I always cautioned against the presumption that his time was up. He is at once a survivor, and an extraordinary comeback merchant.

For those, like me, more focused on tennis than on politics at this time of year, declaring him finished is akin to switching off the television when Novak Djokovic is two sets down, presuming that you’ve seen the last of him. You haven’t.

However, as surely as night follows day, there was always going to be a straw that broke the camel’s back, obscure as that straw (“Pincher by name, pincher by nature”) turned out to be.

For all his faults, this rogue of a Prime Minister is an extraordinary political force, and it is far from clear that any of the pretenders to the throne around him possess the same abilities: the ability to persuade Leavers and Remainers that he or she is their best bet; the ability to convince shipbuilders from Sunderland and bankers from Berkshire that he or she is on their side.

The lazy narrative, that the Cabinet is full of clowns and so on, is nonsense; there is real talent there. Nadeem Zahawi, Kwasi Kwarteng, Sajid Javid, Rishi Sunak, and current outsiders like Jeremy Hunt. These are highly intelligent, capable people the sort of which, frankly, we could do with at Holyrood. But do they have the ‘it’ factor of Boris? I’m not so sure.

Of course, it’s all relative. The real question is how they measure up, in the eyes of the 2019 Tory voters all over the country, to Sir Keir Starmer.

The Labour leader is a curious specimen. I must confess, I had higher hopes for him in theory than have materialised in practice. That his election as leader was critical for the Labour Party almost goes without saying. Labour was utterly toxic after being decimated by Jeremy Corbyn and those who supported him, and needed someone to recover not only its electability, but its morality.

The job of being Leader of the Opposition is fundamentally at odds with the job of being Prime Minister. It is rare to come upon somebody who does both of those jobs well, with the only example in recent memory being Tony Blair. In opposition, Sir Keir is no Tony Blair but, in my book, he is likely to make a better PM than he is a leader of the opposition.

To get there, he is likely going to have to persuade more of us in Scotland that he is the right horse to back and, like everything in Scottish politics, that will depend largely on the stance he adopts on the prospect of a second independence referendum, and on his vision for the future of the UK.

Together with his excellent Scottish counterpart, Anas Sarwar, he built on that narrative this week, having already nodded towards ‘home rule’ being Scotland’s future. Mr Sarwar called for the abolition of the House of Lords and its replacement with a senate of the nations and regions.

That is not only, in my book, a just replacement for an undemocratic stain, but a building-block towards making it clear to Scots that there can be a version of the UK which more of us can feel positive about.

Sir Keir, for his part, made clear that Labour’s EU policy is to ‘Make Brexit Work’. Not only does that have instinctive resonance as something that is not currently happening, it also respects the choice made by many of his party’s erstwhile voters in the north of England and, lest we forget, by almost four in ten Scots.

The SNP appears to have a rare blind spot on this issue, as I wrote about on these pages last month. The inevitability of a customs border between Scotland and England should an independent Scotland join the EU, renders that outcome effectively dead; Sir Keir’s ambition has a realism which the SNP’s lacks.

Added to the interventions of Sir Keir and Mr Sarwar, Labour’s Mayor of Greater Manchester, Andy Burnham, this week told Scotland that we were missing a trick by not having elected majors in our biggest cities and that, indeed, would also play its part in persuading Scots that we can exercise significant democratic decision-making close to us without the need to leave the UK.

Labour, we can see, is starting to create a skeleton of what a new version of the UK might look like under Sir Keir’s leadership. When the rest of the bones are in place, what it needs is the flesh to make them credible, in the form of detailed policy, and the muscle to make them more electorally attractive, in the form of the people at the forefront.

In this respect, there is an inevitability which Sir Keir and Mr Sarwar claim not to accept, but which they will have to if they want to see the change, and be the change, that they are proposing.

They will have to support a second independence referendum.

I know they don’t want to. But they know, deep down, that they have to, for the good of their country as well as for the good of their party in Scotland.

Without it, Scotland will remain stuck in a holding pattern of failure, and the polar positions of the SNP and the Tories will always be more attractive than the middle-of-the-road thoughtfulness of Labour.

But it should be Labour’s referendum, on Labour’s terms. It should have two questions: a first asking people whether or not they want constitutional change, and a second asking whether they want any constitutional change to be in the form of home rule or independence.

In 2014, many No voters unenthusiastically opted for the lesser of two evils, despite knowing that there was no vision for the future of the UK. But, next time, they could make a positive choice for change within the UK.

If they choose independence instead, so be it. But there is a reason why the SNP hates the idea of a so-called ‘middle option’ being on the ballot paper. It’s because they think it would win.

Sir Keir should have that in mind when he is fleshing out those bones.

Andy Maciver is Director of Message Matters and Zero Matters