Such is my respect for Spectator readers that I offer you a column whose subtext is in Latin. Ours is one of the last mainstream magazines among whose readership the phrase mutatis mutandis will be very widely understood.

But the little test you and I are going to try concerns a live issue, not a dead language. For the purposes of this test I am going to paint you a scenario, and you’re going to give me the broad thrust of the advice you’d give in such circumstances.

Imagine that the Labour party has been trying for some time to position itself firmly on the centre ground. The strategy (you may remember it from the days of Tony Blair) is to break out of the party’s ‘core’ support, and attract enough floating voters — those people who can imagine themselves voting Labour but might in other circumstances vote Conservative or Liberal Democrat — to nudge its poll ratings towards the 40 per cent mark necessary to gain an overall majority.

The repositioning had been going reasonably well. But Labour strategists have now encountered a problem. All their centrist talk has produced a backlash from ‘old’ Labour and the left. Particularly unsettled have been the trade unions. A ragbag of renegades, led by a colourful, Ken Livingstone-like figure and united by the belief that Labour has lost sight of its proletarian principles, have formed a party of their own. They’ve called it Socialist Action for Real Democracy, or Sard — its supporters being dubbed Sardines. The Sard poll ratings struggle to approach two figures but the party’s message is simple and chippy. Sard’s appeal to a minority who want to punish Labour for betraying their traditional values brings it (some argue) within sniffing distance of cheating Labour of victory in a swath of the party’s marginal seats. The Sardines threaten to spoil Labour’s hopes of winning.

Argument is joined. Some Labour voices, while remaining loyal, proclaim the need for Labour to do a deal nationally with the Sardines: perhaps an electoral pact. Others suggest ‘local’ deals in which Labour candidates prepared to sign up to some of Sard’s key demands are given a free run in their constituencies. The New Statesman has just run a whole issue — ‘Why cleft the left?’ — devoted to the case for Labour’s trying to answer the anxieties of the old left, accommodate some of its aims, trim ‘new’ Labour’s centrist tendencies, and reach out sympathetically to what some have called Labour’s Sardine ‘cousins’. The magazine’s contributors are wary of direct dealings with the Sardine leadership, and instead recommend a ‘bottom-up’ appeal to the kind of old left voters that Sard seem to be hauling in.

The New Statesman voices advocating this approach are themselves to the left of Labour’s leadership. Some are borderline Sardines themselves. Some would make any excuse to import parts of the Sard manifesto into official Labour policy. But they have convinced themselves they are proposing this leftward lurch not as a way of pursuing their own ideological agenda, but in the broader electoral interests of the Labour party.

Now, reader, give me in note form the gist of the advice you’d offer Labour: your answer to the question ‘Should Labour stick to its centrist guns — or cast its net on the other side, the port side, in an attempt to net some Sardines?’ Surely you’ll almost all give me the same response? Something like this:

Labour would be crazy to lurch leftward to pick up lost voters — huge implications for appeal to centre ground — for every disaffected voter ‘floating’ away to left, dozens of more centrist voters who’d then float away to right — millions antagonised by sight of party cuddling up to a fringe party branded as extremist — ‘Labour Sups with Sardines’ would be big media story — headlines about party returning to bad old days — Tories will start calling it the Sard-Labour alliance — no, message to Labour must be ‘Keep your heads, stick to your centre-party strategy’ — that’s where the votes are.

Have some of my Spectator colleagues gone crazy? There’s a huge hole in the argument for cuddling up to Ukip in order to win back its supporters. The hole is so obvious I hesitate even to rehearse it before a readership which must be presumed to be of sound mind, but it’s this: Ukippers are an identifiable group and a noisy and colourful one, but even at the highest estimate are less than 10 per cent of the electorate. Potentially much larger, however, but amorphous because they don’t self-identify and don’t strongly support any party, are the millions who might vote Conservative, might vote Liberal Democrat, might vote Labour, or might just stay at home. Every general election the Conservative party or the Labour party have ever lost, they have lost because enough of these voters have floated away; every election either party has ever won has been won by winning over enough of them.

By definition this group is unable to make demands, offer pacts or bang its drum in the media, but through polling we do know a bit about what worries it about the Tories: that they appear ‘uncaring’, that they are ‘too ideological’ or ‘right-wing’; and we know that women are more likely than men to harbour such doubts. It is perfectly true that some of the positions that some of these voters may take on issues like immigration, crime and punishment, or the EU, are positions that Ukip take, too; but if the Conservative party lurches into Kipper-talk then it will simply not be believed, because it is a party of government and in their hearts the voters understand that responsible government cannot wave a wand and do all the things that the rest of us like to let off steam about. In the eyes even of voters who espouse kipperish positions on policy, the Tories would look ridiculous pretending to be Kippers.

Remind yourself, then, of the reasons Labour would be crazy to lurch left to pick up more of the ‘old’ Labour vote, and ask yourself why this reasoning does not apply to the Tories, and a lurch to the right. Mutatis mutandis, that is.