Sketch: Cloddach Bridge creates a divide between Douglas Ross and Deidre Brock

When two people really don’t like each other, they’ll find literally anything to argue about. In this case, it was a bridge.

The SNP’s Deidre Brock was unhappy about a bridge 150 miles north of her constituency. Tory Douglas Ross, whose constituency contains the bridge, was rather content with it. Fertile ground, then, for a spat.

The questioning of the Scotland Office ministers by the Westminster committee began cordially enough. Brock was asking about levelling up funding decisions. But then she got onto the levelling up of the bridge.

The SNP, as we know, is rather opposed to building bridges – it benefits far more from division. And Brock seems to suggest the reason this bridge was getting £1.5m was because of where it is. “There have been questions raised about the bridge in Mr Ross’s constituency,” she says.

The Conservatives, always fans of building bridges (remember the one to Northern Ireland?), get rather defensive about the whole thing.

“Can you name the bridge?” interrupts Ross. Brock cannot. “Well maybe don’t ask about something you don’t…”

This becomes a bit much for the SNP. Brock suggests Ross should enlighten her, while her party colleague Pete Wishart also intervenes, cutting Ross off with an “order, order!” But Ross loves the bridge too much to let it go.

“It’s called Cloddach Bridge,” he continues tersely. “Ms Brock has spent a large chunk of this time...”

“Right, ok,” says Wishart, clearly wishing to avoid a rammy, but Ross cannot contain himself.

“No, if I can, chair…” Ross says.

But Wishart, who dislikes nothing more than being interrupted and having the spotlight stolen, yells: “No, you can’t!”

“So you’re not allowing a member to speak,” Ross replies flatly. He’s tried this tactic before, accusing opponents of shutting down debate. The man loves free speech almost as much as bridges.

Wishart is having none of it. “We’re going in a particular order,” he says. “Ms Brock is asking questions.”

“I’m finished now, chair,” Brock mischievously intervenes. Her work here is done; Ross rose to her bait. She sits back with a look of contentment.

Ross, unable to let anyone else have the last word, mutters: “Well thank god, because it’s been going on for quite a while.”

Honest Jack barrels on: 'I’m honest, it’s an honest position, they want to destroy the United Kingdom.'

Tensions momentarily brought back to a simmer, Wishart hands over to Conservative David Duguid who asks the Scottish secretary to tell him about the benefits of some legislation or other. A nice softball question.

But if a bridge is enough to get the blood pressure up, that’s nothing compared to claims of who is protecting or denying devolution.

And Alister Jack came out swinging on that front. The Scottish secretary tells the committee: “The Scottish Government get up each day and go to work to destroy the United Kingdom. I get up and go to work each day to strengthen the United Kingdom.”

But, he insists, the two governments are still working very well together. That’s because he’s just an “honest” man, he says, who likes to point to the elephant in the room before ignoring it.

Wishart is unsure about such manoeuvers. Such “inflammatory” language, he argues, is not good for working relationships. He innocently asks: “I just wonder how helpful you think, like, ‘destroy the UK’, that type of language is…”

Honest Jack barrels on: “I’m honest, it’s an honest position, they want to destroy the United Kingdom.”

“There’s being honest and there’s using language that is not in the least bit constructive,” Wishart retorts.

“But I’m honest!” insists Jack again. “The Scottish Government want to break up the United Kingdom which would bring devolution to an end.” Which is technically correct, really, thus further proving his honesty.

Ross isn’t sure how well this line of argument is going down. But he is handily armed with his own searing retort. “Earlier this morning we heard the depute leader of the SNP on Radio Scotland referring to the UK as acting like a rogue state.

"The former first minister accused people who disagreed with her Gender Recognition Reform Act, of  ‘they’re transphobic, they’re deeply misogynistic, often homophobic and some of them are racist as well’.”

Every slight about his bosses made by the SNP is written down in a little book, which he can whip out at any moment. “Do you think that’s some of the language the chair was referring to?”

Jack concurs. “It is inflammatory language,” he says. The Scottish secretary wonders aloud whether the Scottish Government is “looking for grievance where none existed”.

But Ross isn’t done. Still smarting about being cut off earlier, he accuses his opponents of being “clearly ill-informed because Ms Brock couldn’t even name Cloddach Bridge!” Apparently that was a bridge too far, even in these politically torrid times.