Ouch. The SNP government is behaving like a "big baby", according to spokespersons for the UK Work and Pensions Secretary, James Purnell, and it's time to start slapping its bottom. No council tax rebate. No consultation on firearms. No Lewis chessmen. It's off to bed and no watching the footie on telly!

There has been a marked change of tone in Westminster's dealings with the delinquent Scottish administration in Holyrood over the past couple of weeks. After the Prime Minister's apparent concession on tax-raising powers for the Scottish Parliament three weeks ago, there seems to be a feeling that it's time to start showing the upstart Nats just who is really in charge. Who the big boys are. And remind Scots that the real government of Scotland is not the SNP, but Labour, who won the last General Election.

Well, good luck to them. For if this is the new strategy then it is an unwise one. The rejection by the Home Secretary, Jacqui Smith, of a summit on banning air guns seems particularly pointless - a case of shooting yourself in the foot while attempting to place it in your mouth. Labour in the Scottish Parliament has already signed up to a review of air weapons, and the tabloids are behind stricter controls since the shooting of toddler Andrew Morton in 2005. Around eight out of 10 Scots seem to approve a ban, as do the police and the other political parties.

As it happens, I don't. I think we are becoming rather too obsessed with banning everything in sight and it would take a lot to convince me that airguns really are such a threat to life. However, it would be politically pointless for the UK Government to defy Scottish public opinion on such a relatively minor issue, and I can hardly believe that they're serious about doing so. Haughtily refusing to endorse the review just plays into the SNP's hands.

Nor am I a great enthusiast for local income tax. I just don't understand why working couples, struggling to buy a home, should subsidise wealthy older people living on unearned income in big empty houses. But again, the political parties in Scotland have all more or less accepted that the council tax is a disaster and politically unsustainable. And who am I to argue?

The proposal to scrap the council tax was a major vote winner for the SNP, and I doubt if Labour in Scotland is really prepared to go to the wall again in another election in order to save the unloved tax. The Liberal Democrats, at their conference in Aviemore this weekend, reaffirmed their commitment to local income tax and there is a clear majority in parliament for introducing it - though there are differences of view about how exactly to go about it.

But in walks Secretary Purnell of the UK Government, and says NO. He doesn't mount a coherent argument against the tax on moral or economic grounds, but threatens in a newspaper interview to cut off council tax benefit, currently worth £400m, if the Scottish Parliament goes ahead with local income tax. "If they are promoting a system that is income-related and based on the ability to pay, then there is no need for a benefit on top of that. They can't have it both ways."

This is eerily reminiscent of the refusal by the former Work and Pensions Secretary, Alistair Darling, to allow attendance allowances to be recycled to help pay for free personal care back in 2001. The recent financial difficulties of free personal care are largely down to the cumulative effect of the UK Government's refusal to maintain the level of financial assistance to care of the elderly that existed before the policy switch. It was an act of vindictive pettiness which did absolutely no good to Labour in Scotland. And nor will this attack on local government finance.

When Westminster scrapped the rates, it didn't abolish rates reliefs; when the poll tax was scrapped, local government subsidies were transferred intact to underwrite its successor, the council tax. It is not for UK ministers, acting like colonial governors, to make arbitrary rulings about how Scottish taxpayers' money should be used in Scotland. The £400m that currently goes in council tax benefits is part of the overall structure of local government finance - which already mostly comes from recycled income tax, since council tax raises only a small proportion of what councils actually spend.

This is just spite. Even as I read the quotes in the press yesterday, saying that the SNP was behaving like a "big baby" I couldn't believe that Westminster could be so stupid. By all means challenge the intellectual credibility of local income tax, but to adopt this kind of patronising attitude just delivers votes for the SNP. It speaks volumes about the attitudes of the London Labour administration and its detachment from the reality of Scottish political life.

Labour likes to criticise the SNP leader Alex Salmond for picking fights with Westminster, for manufacturing grievances for political ends. But he hardly needs to because the UK ministers are doing the job very well for him already. They seem to forget that Salmond isn't the prime minister or president of Scotland but the First Minister of a minority government. He can only act on issues such as local income tax by consensus, by the agreement of the other parties in the Scottish Parliament. This means that when UK ministers attack Salmond on issues such as airguns or local income tax, they are not attacking just the SNP, but the consensus view of a proportional parliament. In other words, they are attacking the people of Scotland.

The policy of local income tax is already posing problems, as will be clear in the Scottish Government consultation paper that is due to be published in two weeks. There are important issues about how to ensure local accountability if councils are just going to get a slice of centrally raised income tax.

There are questions to be answered about how local income tax should be collected, and whether there would need to be a Scottish Revenue established, and about the impact on two-income families. However, the one way to divert attention from these difficulties is to suggest that London is arbitrarily going to cut local authority funding as a punishment for a democratic decision to abolish council tax. It really is the politics of the nursery, and it's time for UK ministers to grow up.