A BEAST from the east. Visibility low to zero. Competing choruses of advice, one crying “Turn back, turn back,” the other insisting “Plough on, we’ll get there in the end.” If you were in the market for a Brexit metaphor yesterday, the red alert weather supplied it with knobs on (handles manufactured in accordance with EU regs, for now).

Like the weather, no-one can say they were not warned what was coming. Sure, it was almost possible, just before Christmas, to pretend that the December agreement forged between Theresa May and the EU was more than some Guinness Book of Records attempt at fudge-making.

But now March is upon us and with it the publication of the EU’s draft withdrawal treaty, complete with its controversial proposal for a “common regulatory area” to avoid a hard border between Northern Ireland and the Republic. Things were meant to be clearer come the draft treaty, except they are not. With Mrs May declaring in the Commons yesterday that no Prime Minister would ever agree to such an idea, which would keep Northern Ireland in the customs union and in effect still part of the EU, Brexit is once again heading for the cliff edge. In this political weather that is not a place anyone with any sense would want to be.

As with any competition between political forces, there has always been a whiff of the Darwinian struggle about Brexit. A political leader has to be fit to survive, but above all they have to be bolshie, to go with the flow of chaos rather than feel overwhelmed by it. On that score, Mrs May can learn much from those who seem to be doing their utmost to add to her difficulties, among them that original constitutional troublemaker, Nicola Sturgeon.

Since the Brexit process began Mrs May has consistently given the impression of a Prime Minister who is being led by events rather than someone who is showing the way. How could she, a Remainer, be otherwise?

This was not a battle of her choosing. She is not, by instinct, a politician who relishes living in interesting times. Her entire career before Downing Street was built on the notion of safety first. On the one major occasion on which she went against her nature and better judgment, in the calling of a snap General Election, she came a cropper.

Her survival since then has been dependent on keeping away from the Brexit fray as much as possible. Let the Tory troops fight it out amongst themselves until they get to the point where the only choice ahead is carrying on with her, or launching themselves into the great unknown of another General Election that Labour might win. Simply by appearing reasonable, giving a little here, asking for a little there, she has kept the process going. She has been the blank page on which competing forces could write their demands. The details could wait, the cheque remain unsigned.

It has not been the worst way to proceed. Given her warring party it was likely the only way she could have gone. But now the time for details has arrived, and her speech tomorrow, setting out her vision for the UK’s relationship with the EU post Brexit, has to reflect that change. It must show that she can adapt, that she is able for the fight, not least against those who would have her throw in the towel and settle for a hard Brexit now that the going is getting tougher.

The Friday speech is at the top of her to do list. Scotland, much as we might like it to be otherwise, is further down that list. But the fact it is still there, and relatively near the top, is down in large part to one of two things, depending on one’s point of view: firm but friendly lobbying on the part of the Scottish Conservatives, the party’s Westminster contingent to the fore; or Scotland’s First Minister being a primo pain in the constitutional settlement, as shown this week in the publication of a Brexit Bill to rival Mrs May’s.

Most grown ups, if asked, would not set too much store by the sway of the Scottish Tories. Mrs May, her doubtless warm words at the party conference aside, does not. She can count on their support; they are not going anywhere. She does not need them the way she needs the DUP. When it comes to her survival, Scots Tories, to borrow a metaphor from Sir Martin Donnelly, former Trade Department mandarin, are a packet of crisps compared to the DUP’s three course meal.

Similarly, it might be argued that Ms Sturgeon’s threat to refuse legislative consent for Westminster’s EU (Withdrawal) Bill amounts to very little in the grand scheme of things. Critics might say it is a supreme example of bluffing, one that, should the matter go all the way to the UK Supreme Court, could be nothing but a costly distraction to the Brexit matter at hand. That will be for Ms Sturgeon to answer, should it come to it.

But if she achieves nothing else for now, the First Minister has at least shown she is prepared to take the initiative and will not be brushed aside so easily. It is not pretty politics, it is not even especially clever politics, but carried out in conjunction with the Welsh Government, it is likely to be effective. If it is not, and Westminster is seen to impose its will on Holyrood, that can also be notched up as a “win” for Ms Sturgeon. For someone who has thus far played a truly dreadful game on Brexit, starting with her unseemly and politically costly rush to use it as an excuse for indyref2, it is a smart change of tack.

Between Ms Sturgeon’s legislative manoeuvres and Jeremy Corbyn’s U-turn on “the” customs union, being audacious now looks like the only way to beat the hard Brexiteers at their own game. Does Mrs May have it in her to do the same? Unless the EU negotiators are even worse at their trade than their UK counterparts, they surely expected a rebuff on the common regulatory area idea. In calling it a “backstop” they admitted as much. Now, more than ever, the way is clear for Mrs May to seize back the initiative with a bold, workable alternative of her own, one that will show she is her own woman and in charge. Time is running out. If she cannot take control now she never will.