THERE was a mouse at FMQs. The parliament’s positively bulging with the things, scurrying round the MSP block, nibbling expense claims, but you don’t often see them in the chamber.

You couldn’t miss this one. It was sitting in the Presiding Officer’s chair.

“Excuse me, excuse me,” it squeaked periodically. “Can we have a little bit of order please?”

Everyone ignored it. “Will members please settle down?” it begged. They just got noisier.

Poor Ken Macintosh, he made less of an impression than an arse on an anvil.

“There are too many interruptions and too much shouting,” he peeped at one point in the din.

Perhaps it was the absence of Nicola Sturgeon that turned the proceedings so riotous.

The cat was away in London and so Deputy First Minister John Swinney had taken her spot.

The subject was oil. Before the last independence referendum, the SNP claimed it would be “a bonus” for the economy, a sort of triple chocolate frosting on the cupcake of life.

Then the price collapsed and all that was left to spend were the crumbs.

Or so, roughly, said Andrew Wilson, chair of the SNP Growth Commission, this week when he admitted oil wouldn’t have been a “bonus” but a “basis” of the budget.

“The entire economic case for independence was bogus,” thundered Ruth Davidson.

“The economic case for independence is well and truly bust,” declared Kezia Dugdale.

But Mr Swinney, despite being reminded he too had predicted a “massive North Sea oil boom”, was ready for them. He didn’t have anything to say, but he said it brilliantly.

Where lesser mortals saw only facts and damning evidence, he sensed opportunity.

Where others saw Tory and Labour rivals, he saw the Yoon and Yang of Better Together.

Sweeping his arms around him and feigning disbelief, he had the SNP benches in uproar.

“Is it not revealing that at the first available opportunity Labour and the Tories have come together again?” he asked. “It is like they have never had a moment apart.

“I would have thought that, after the calamity that Kezia Dugdale led the Labour Party into in the 2016 election, she might have learned to have nothing to do with that lot over there!”

He jabbed a triumphant finger in Ms Davidson’s direction. The rest of the session was the same. As the rhetoric got emptier, the Nationalist cheering simply got louder.

“Can we have a little bit of order, please, and slightly less applause?” whispered the mouse.

Mr Swinney shooed it away. “The arguments, narrative and explanation that Kezia Dugdale is coming out with today - her entire line of attack - could have been delivered by Ruth Davidson. I have some helpful advice for the Labour Party: it should get on to Scotland’s side!”

Cue general pandemonium and a sigh of resignation from Nibbles Macintosh.

What Ms Sturgeon will make of being outshone by her deputy remains to be seen.