POLITICIANS are like shale beds, we learned at FMQs: put them under pressure and all sorts of dreadful gas comes out.

Kezia Dugdale demonstrated this scientific phenomenon by squeezing Nicola Sturgeon over the SNP’s infinitely flexible position on fracking.

It started with a rope-a-dope, as the Labour leader mocked the FM for keeping the “hated council tax”, despite endless vows to scrap it.

“She could have broken her promise on day one, so why did it take her 10 years?”

The FM insisted her negligible tweaks to the levy were fair and reasonable.

“That’s probably why Labour opposes them,” she sniffed.

Ms Dugdale then crunched gears and veered off-road: “Here’s the SNP’s formula: condemn it, freeze it, order a big report, do it anyway. That’s not just the approach to council tax.

“The SNP says fracking is bad and has imposed a temporary freeze. A big report’s been ordered. But all the signs are the SNP will do it anyway.

“Labour would not allow fracking in Scotland. Can the FM give the same guarantee?”

Blindsided, Ms Sturgeon started releasing bubbles of pure nonsense.

“Before we move on from local taxation, which I’m still keen to talk about-” she began, before bumbling through a pre-cooked attack on Labour.

“On the issue of fracking,” she remembered eventually to ironic cheers, “we will not allow fracking because we will not take risks with our environment while there are still unanswered questions. That’s why we have a moratorium in place.”

Ms Dugdale accused the SNP of shambolic fracturing on the issue: MSPs against it on their election leaflets while ministers researched its lucrative potential and reassured would-be fracking giants Ineos.

“If Ineos can get a straight answer, why can’t the people of Scotland? Fracking: yes or no?”

The FM belched on about her moratorium, but didn’t address what lay beyond it. “Labour say whatever they like because they’re going to come second in the election,” she fumed.

Afterwards, the FM’s official spokesman declared she was actually “highly sceptical” about fracking, although in what way he couldn’t say. Voters had best be highly sceptical too.