DEPUTY leadership contests don’t generally set politics alight. If you asked most people in the street to name the current British Labour deputy leader, a few people might mistakenly suggest the name of John McDonnell – though I suspect most people would just look at you blankly.

And who is the deputy leader of the Scottish Conservatives? No prizes for guessing it’s David Mundell – because you’d be wrong. And as I write this, I cannot for the life of me remember who the deputy leader of the Scottish LibDems is.

So, it’s fair to assume that the contest to replace Angus Robertson will not be provoking raging arguments in homes and workplaces across the length and breadth of Scotland over these next few months.

Yet so dominant has the SNP become in Scotland, the outcome of this contest does matter beyond the circles of those who eat and breathe politics on a daily basis. Last time around, I was struck by the number of window posters on display in Glasgow in support of Tommy Sheppard’s candidacy.

When did an internal deputy leadership election ever before resonate so strongly with at least a section of the wider public? Probably not since the early 1980s, when Denis Healey beat Tony Benn by a fraction of one per cent to take the number two spot in the Labour Party. Had that knife-edge contest gone the other way, who knows what the long-term impact might have been? New Labour may well have never come into being, and Tony Blair might have remained an obscure barrister.

Although I don’t have a vote in this election I will be watching it with some interest, because it will give us a clue about the future direction of Scotland’s biggest party. And for the wider independence movement beyond the SNP, that matters.

Most big political parties are an uneasy coalition of forces. For decades there has been periodic and vicious blood-letting in the Tory Party over the European Union – and that looks like it’s about to escalate in the run-up to the autumn conference season. The Labour Party was always a battleground between right and left, until the New Labourites swept all before them in the 1990s and early 2000s. For now, the pendulum has swung to the left, but woe betide Jeremy Corbyn and the left if they fail to deliver a victory in the next General Election.

The SNP, too, has always been what is sometimes euphemistically described as a “broad church”. Alex Salmond was famously expelled in the 1980s for being part of a left-wing cabal. And a party that can today comfortably accommodate Fergus Ewing and Mhairi Black can’t ever be accused of being a narrow, ideological sect.

That’s been one of the strengths of the SNP – but such a wide coalition can only be sustained until Scotland achieves full independence. At that point, I suspect the ideological differences that have been held in check for decades will start to erupt.

I realise that the SNP membership may be tempted to play it safe when choosing Robertson’s successor. After all, the party remains way out in front of all challengers, despite more than a decade in power. Support for independence is holding up and might surge ahead in the near future. The prospect of the triumvirate of Boris Johnson, Michael Gove and Jacob Rees-Mogg taking control of the UK Government by the end of this year could create a whole new dynamic. So too could the potentially catastrophic consequences of a Tory Brexit.

But we don’t know for sure what the future will bring. What we do know is that, although the SNP is ahead in the polls, the pro-independence parties still lag behind the pro-Union parties.

So, should the SNP continue along the same careful path, progressive on social policies, leaning a little bit to the left economically, but frustratingly cautious to the point of timidity? Or should it shift more decisively in one direction or another?

Anyone who reads this column, or knows my political background, won’t be surprised to find out that I would like the SNP to be more robust in challenging big business and the establishment, and bolder in offering sweeping change.

There are also strong tactical reasons why the SNP should avoid at all costs dawdling in the middle of the road.

To drive forward towards independence, the party has to win back votes from either of its two biggest rivals, the Tories or Labour. The Scottish Conservative and Unionist party is exactly what it says on the tin. It is Unionist to its red, white and blue core, so there ain’t many votes in that direction for the independence cause. Labour is a different kettle of fish. Its support base is more open to change, less committed to the United Kingdom, and probably less than inspired by the performance so far of its new Scottish leader.

Robertson is a capable individual, and good luck to him in whatever new career he pursues. But I would like to see him replaced by someone very different. Someone with a radical edge. Someone who will help fire up the young, the poor, the urban and rural working classes. Someone who is an authentic voice of the people rather than a polished politician.

And someone who, if they happen to be a Westminster MP, will spend most of their time campaigning in Scotland to build support for independence rather than wasting their time in London squabbling with the privileged public schoolboys of the Tory Party.