For connoisseurs of the art, it is a lovely piece of sophistry.

Fans of the all-weather, multi-purpose double standard might also find something to admire. The rest of us can only pause to wonder if Conservatives care at all about the future of the United Kingdom.

Here's how it goes. If you are one of 56 of Scotland's 59 MPs you have no right to complain, it seems, when every last one of your amendments to a Scotland bill is overruled by English parliamentarians. You are members of a unitary British legislature, a fact confirmed in a referendum, and those are the rules. Lump it.

If, however, you decide to live up to your responsibilities and exercise your rights as a member of that parliament, you will be crossing a line. According to Murdo Fraser MSP, indeed, you will be "stirring up hatred" if you so much as propose - the piquant part - to overrule English Tory MPs. Blood-curdling warnings will follow.

Those work well. Tantrums having failed and facing defeat, the Conservatives have decided to fiddle with the rules. There will be no vote on reforms to the Hunting Act until the autumn. By that time, supposedly, Scotland's MPs will somehow have been excluded from the process. In other words, if and when the English Votes for English Laws (Evel) shambles is resolved, the hunting shambles might be sorted out.

Let's be clear. It doesn't matter what the SNP said previously about fox hunting in England and Wales. The election and the refusal to recognise its relevance to the Scotland Bill altered cases. The "self-denying ordinance" preventing votes on England-only matters was always a gesture, not a piece of solemn parliamentary procedure. After barely two months in office, David Cameron's Government is making a habit of backing down. That trumps chatter over SNP U-turns.

Besides, if the Nationalists had taken all that Better Together rhetoric to heart, they would simply be doing their properly British bit in all aspects of the British Parliament's business. Right? Wasn't that supposed to be the meaning of the referendum result? Wasn't it all a great partnership of equals, especially at Westminster? "But you said you wouldn't" is a bit rich, at the best of times, coming from the Tory Party.

What is being overlooked, meanwhile, is that fox hunting is a profoundly moral issue for people on both sides of the Border. If such is your belief, animal rights are universal. This is not an argument over roads in Hornchurch or schools in Hull. Rather than ask by what right the SNP thought it could be involved, you might as well ask why it would feel entitled to stand aside.

In any case, though some like to pretend otherwise, there is, as yet, no such thing as Evel. David Cameron's attempt to tinker with Commons standing orders failed, and failed precisely because he showed no respect - you could love the irony - for the rights and traditions of the British Parliament. Thanks to the referendum, the SNP is stuck with that institution. So too - and isn't this what they wanted? - are Tory MPs.

They can threaten consequences. What would those be, exactly? It is argued that the SNP was stepping into a trap with its "provocative" (as one English paper has it) decision to participate in the fox-hunting debate. The Government's shenanigans over the Scotland Bill, in contrast, were not deemed provocative, or calculated to offend, or in any way wilful. Those were just part of what it means to have a British parliament. Where's the difference?

That the SNP has caused bad feelings? If it had voted with the Commons majority against the fox-hunting reform it would have offended only a parliamentary minority. Such minorities are often offended, as Tories sometimes blithely observe. But will not resentments be stored up for the future, and shouldn't these be avoided at all costs? That might be a lesson for Mr Cameron to learn before he lectures anyone else.

The Prime Minister and his Cabinet have been going hell for leather in pursuit of their legislative programme. This is due partly, no doubt, to pent up desire: zeal abounds. But the Conservatives are also in a race against time, rushing to get their business done before their 12-seat majority shrinks away and life becomes difficult. As things stand, Evel will not delay the process by much, if at all, whatever Mr Cameron might hope. Then what?

In that context, he has made a tactical error over foxes. During the last Parliament, the Conservatives Against Fox Hunting Group claimed 28 members. A handful of Labour MPs stand with the fox-killers, but the Prime Minister was in difficulties even before the SNP decided to become involved. One way or another, the vote would have been too close for comfort.

Blaming the Scots might suit Downing Street just as it publishes its "Revised Proposed Changes" to its Evel scheme. It will help not at all when the issue is Europe and the Government has demonstrated weakness. It is blindingly obvious, equally, that restricting the rights of Scottish MPs would not save the fox-hunting reforms: an SNP intervention would still be decisive. It is startling - and revealing - that several Tory MPs seemed unable to grasp the fact yesterday.

Perhaps they have a sturdier version of Evel in mind than the one on offer. If so, you can forget all the fine talk about the sanctity of Union, paramountcy, and a unitary parliament. In that case, the festering resentment of Tory backbenchers is neither here nor there. It is a curious, craven view of politics, indeed, that says they must never be upset lest they do something rash. If they have a notion to exclude Scottish MPs entirely from England-only laws, it is they who can face the consequences.

Those Conservatives seem to have imagined that Scotland could return SNP members by the dozen and nothing important would change. They know better now. They don't care for it: never mind. But to pretend that some great offence has been offered because Scottish MPs decided to act like MPs is an odd sort of Unionist response. To behave as though - dash it all - Westminster is not supposed to work this way speaks volumes.

Crudely, it's tit-for-tat politics, a business of competing claims, a question of who might be overruling whom. Two things are therefore clear. First, it is not the business of the SNP to worry about the bruised pride of Tory MPs, or worry unduly about retaliation. What could the Conservatives achieve with that?

Secondly, in case anyone forgot, holding the Union together is not exactly the Nationalists' purpose. Evel, a piece of expediency from Mr Cameron, is not the solution to the United Kingdom's problems. He has no discernible interest, meanwhile, in the forlorn hope of federalism and his majority is fragile. Increasingly, his backbenchers will fume and the SNP will conduct the business of opposition by any means available. Sooner or later, matters will come to a head.

That joke about attempting to shoot the Nationalist fox - and missing - goes here.