THE blokes in blue came knocking for Nicola Sturgeon this week. The new intake of Scottish Tory MPs - and with one exception, they are all blokes - were crowing about the Budget.

Philip Hammond had just announced that from April 2018, Scotland’s national police and fire services will no longer be liable for VAT. Like their counterparts in the rest of the UK, they will be able to reclaim it, saving £40m a year.

It was, on the face of it, a climbdown by the Chancellor. The UK government had refused to grant the Scottish forces a VAT exemption since they were created in 2013.

Meanwhile, with increasing stridency, the SNP had been demanding the change in order to end what they said was Tory spite.

So why were the loudest cheers coming from Tories over a U-turn, and all the gnashing of teeth from the SNP, who got what they wanted?

The heat and noise generated by the VAT row is out of all proportion to the sums involved. The £140m paid out in VAT since the police and fire mergers is around 0.1 per cent of the Scottish budget over the same period. The annual underspend is usually more than that.

The issue also was due to be partly-mitigated by increased financial devolution. From April 2019 half the VAT receipts generated in Scotland will be assigned to Holyrood rather than go to the Treasury. The Fraser of Allander and Chartered Institute of Taxation say that means half the VAT that would have been paid by the emergency services would have come back to the Scottish Government anyway.

No, this has largely been a row about politics. The Chancellor’s move makes that explicit.

On one level, it’s been a blame game. Back in 2011, when the SNP Government published its case for reforming police and fire, all three options it suggested factored in a change to the VAT regime.

Until that point, because they were partly funded through local taxation, the regional police and fire services could reclaim VAT. But merger into national forces came with a switch to central government funding, and so this ability was lost.

Six years ago, the government estimated this would cost around £25m a year, and so it proved.

“The Scottish Government has made the decision to go ahead with these reforms fully sighted on the likelihood that the VAT refunds would be lost,” the Treasury told a Holyrood committee in 2012.

On both the imposition of VAT and the size of the bill, the Scottish Government had a very keen sense, right from the outset, of what it was getting into. There was no trap, no surprise, no trickery. VAT payments were built into the business case for reform from the off, although ministers and the services themselves said they would much rather avoid them.

But the VAT issue did prove a useful stick to beat the Tories. Not much at first. SNP ministers wrote to the UK Government about the issue only once before the mergers.

But they wrote to them 12 times afterwards. This coincided with the police reforms in particular going rather badly. VAT became a useful distraction, a handy riposte for ministers to cite when questioned about the deeper problems with the force, such as its yawning deficits (despite the VAT bill being budgeted for), service cuts, dysfunctional management, not to mention a chief constable on leave facing multiple complaints about his behaviour.

There has been politicking on both sides, of course. When Mr Hammond said he was ending the VAT liability, he credited the 13 Scots Tory MPs for bending his ear.

“My Scottish Conservative colleagues have persuaded me that the Scottish people should not lose out just because of the obstinacy of the SNP Government,” he said.

Responding, SNP Westminster leader Ian Blackford attacked “the vindictiveness and nastiness of the Tory government” for imposing VAT.

The row was reprised at Holyrood the next day when Nicola Sturgeon said the Tories had refused to do the right thing “until they thought they could wring some party political advantage out of it”.

Extracting party advantage from a Budget - whatever next?

The outrage was faux, but the pain was real. This was a gut punch to the SNP. It was about voter calculation at its most basic and brutal. Every election boils to the same pitch: “Vote for us not the other bunch, because we can do more for you than they can.”

For years, that has sounded laughable coming from Scots Tories.

But with their new MPs, the dynamic has changed. Of course the VAT change was political. But that’s politics. Hammond is always going to throw his allies a bone rather than his enemies. He wants those Scots Tories to show voters some results and get re-elected.

One Tory strategist tells me VAT is part of a plan to dismantle the SNP’s core narrative that it is the party standing up for Scotland.

The Tories see the election result in June as a breach in the SNP’s defences and they intend to pour through it. The SNP might talk a good game, they’ll say, but it’s the Tories who the get results.

Hence the acute SNP pain. Not only did they lose the stick they were beating their opponents with, the cheeky blighters paraded around boasting about the U-turn.

There will be more of this, and the SNP, as their pained expressions showed, can see it coming.