Nicola Sturgeon ups the ante in the indyref2 stakes

First Minister and Prime Minister will be exchanging letters this Christmas - but there will be little goodwill.

The letter is in the post but it isn’t a festive good wish from the First to the Prime Minister, rather a demand that Boris Johnson agrees to a legal basis on which to hold a second referendum on Scottish independence.

Nicola Sturgeon’s morning media conference at Bute House was a further, expected demand on indyref2, a fleshed-out case arguing that her mandate is as clear cut as it is unarguable. 

It was, however, also a careful, even studied exercise in the field of political caution.

She was straight on one point, she fully expects the Prime Minister to say ‘no’. She was, though, not at all forthcoming on what she will do when he says no, saying she will look at all options.

On suggestions put to her, she would not be drawn, all of which will lead to a charge by opponents that she has no Plan B apart from being a dedicated proponent of political hot air.

In essence, today was more symbolic than anything else, although the Scottish Government upped the ante, reinforcing the message that this is not going away and now formally requesting the power to hold another plebiscite.

One week on from the general election, the constitutional stand-off it created defines the fault-line in Scottish politics for 2020.

The First Minister’s caution is understandable. There will be all sorts of suggestions from the wider ‘Yes’ movement in the coming months about taking on Westminster.

She will simply not countenance anything which is either potentially illegal or which shifts the focus away from the right to hold a new vote and on to the tactics being deployed by her government.

For his part, Boris Johnson couldn’t be clearer. It’s no today, tomorrow, next year and for the whole of the duration of this UK Parliament. This is not an entirely risk- free strategy but it is one that is music to the ears of those voters in Scotland who are frustrated that, five years after indyref1, this is still being talked about.

2020 will see unprecedented levels of tension between Holyrood and Westminster and the first real crisis of substance in the devolved era.

Last Thursday did not end debates on Brexit and independence, it merely shifted them on to other ground, ground on which the battle of the mandates will now be fought.