The news that the Scottish National Party plans to vote against the Government’s amendment to the hunting ban this week means that said amendment will almost certainly fall.

The Daily Telegraph describes Liz Truss, the Environment Secretary, as ‘begging’ Tory MPs to vote for the measure, and ministers at DEFRA are now looking at postponing the vote until after English Votes for English Laws (EVEL) is in place.*

Such are the perils of tackling contentious issues with a narrow majority.

This will mark the first time the Nationalists have voted on legislation that doesn’t affect Scotland in the new Parliament, despite Nicola Sturgeon, the First Minister of Scotland, explicitly identifying hunting as the sort of issue the SNP would abstain on.

Number Ten had hoped they would abstain, not least because this amendment is actually bringing the law south of the border into line with that in Scotland.

In justifying their decision to vote, those defending the deployment of Alex Salmond’s flying column have offered several arguments.

These include the suggestion that the Scottish hunting settlement is a legacy of Labour and they don’t actually support it, and that the Government’s amendment contains some subtle but important technical differences.

There is also the occasional mention of the fact that some hunts may cross the border in pursuit of their quarry, which seems a little weak.

A better insight into their reasoning, however, is probably provided by Angus Robertson, the party’s leader in the House of Commons, who has denounced the Government for treating Scottish MPs as ‘second class citizens’ by proposing EVEL.

Sturgeon has apparently conceded that her decision to let Nationalist MPs break their self-imposed ban on voting on non-Scottish issues is intended to punish the Government for EVEL, and remind Cameron “how slim a majority he has”.

The canny amongst you will already have spotted that an increasingly assertive SNP taking part in non-Scottish debates is scarcely likely to dampen enthusiasm amongst English MPs for reform. It isn’t meant to. Quite the opposite, in fact.

Sturgeon wants to whip up antipathy from English MPs, and tempt them into intemperate language which can then be reported (or misreported) north of the border.

Conservatives should always bear in mind that the surest way to thwart a Nationalist scheme is to remain calm, polite, reasonable, and charitable, even as you work tirelessly against them. To do else is to risk becoming unwitting conscripts to the cause of separation.

Yet a more active SNP also holds perils for Labour. After taking an unexpected pounding in England and Wales over fears of a pact with the Nationalists, the last thing Labour needs is to be seen regularly making common cause with Salmond in the Commons.

It will only make future allegations of a Lab-Nat pact, which looks like the party’s only path back to power given the SNP’s dominance in Scotland, all the more credible in 2020.

*11am Update: The breaking news is that the vote has indeed been postponed.