BORIS Johnson and Ruth Davidson have never seen eye to eye. The Scottish Tory leader made her low opinion of the Leave campaign figurehead clear in the 2016 referendum, and hasn’t tried to disguise it since.

In the Tory leadership contest she backed Sajid Javid, then Michael Gove, then finally voted for Jeremy Hunt.

Now Mr Johnson has returned the favour by making his displeasure with her clear.

First, he ignored her advice to keep David Mundell as Scotland Secretary, replacing him with the unknown but loyal Brexiter Alister Jack.

He then installed an English MP as one of Mr Jack’s ministers alongside loyalist Colin Clark, the MP for Gordon, who cheesily styles himself the “Salmond slayer”.

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Ms Davidson hit back on Sunday saying she could not support a no-deal Brexit - on the same day that Mr Gove said it was the government’s operating assumption.

With the rift widening, the two tried to put on a public show of unity yesterday. Before he met her at Holyrood, Mr Johnson declared himself Ms Davidson’s biggest fan.

Her business-like statement afterwards offered nothing flattering in return, only a passive-aggressive reminder that Mr Johnson had voted for the old deal himself, and her stress on finding a new one.

In other words, no-deal remains anathema to her.

Behind the tight smiles, the differences continue.

No man can serve two masters, says the Bible, and it’s been true ever since.

Scottish Tory members, councillors, MSPs and MPs now face a basic choice - whose side are you on?

Do you back the Scottish leader in abhorring no-deal, or do you back the Prime Minister in accepting it?

Such splits have a tendency to fester for years in parties.

The issue also puts Ms Davidson’s position in doubt.

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If Mr Johnson goes ahead with a no-deal Brexit, can she credibly stay on as leader?

No-deal is not some small policy quibble. It is as fundamental as it gets.

Having declared it a threat to the Union she has vowed to protect, Ms Davidson could not shrug off a Prime Minister who pressed ahead with it.

Mr Johnson would, according to her logic and despite ample warning, be endangering the Union.

That’s the sort of sin Ms Davidson rails against in Nicola Sturgeon. It’s early days. This rift is far from over.