The SNP is the political equivalent of knotweed – but the Scottish parliament election this coming May provides an unmissable opportunity to root it out.

Scotland could then emerge from a long spell of torpor and stagnation and start to draw a line under almost two decades of failure and mismanagement.

For anyone who harbours such a hope, a weekend interview with John Swinney was a depressing foretaste of the possible future that lies in store.

The First Minister said he wants to be a ‘long-term’ leader and confirmed his plan to serve a full term if re-elected – and to stand again in 2031.

He was speaking just before the Christmas break at Holyrood but perhaps he’d already had a tad too much of the festive sherry.

Either way, it’s a depressing forecast because the polls currently predict an SNP victory, although mercifully a majority appears to be unlikely.

John Swinney, pictured with former First Minister Nicola Sturgeon, wants to be a 'long term' leader for Scotland

The SNP's stewardship of Scotland has been dogged with paralysis and inertia

Nationalist rule has been a kind of permafrost for public life, leading to paralysis and inertia, where meaningful reform is off the table (or badly botched).

Take the NHS, which has been judged to be ‘financially unsustainable’ by the public sector watchdog Audit Scotland.

A newspaper profile of the ‘invisible’ NHS chief executive Caroline Lamb, who makes only rare appearances on the front line of hospital care despite earning more than £200,000 a year, contained a telling line.

A political insider noted a ‘weariness in the civil service about suggestions of any reform that might rattle a special adviser to the SNP’.

Those in charge, they told the Sunday Times, had little choice but to ‘manage decline’ – though it’s more of a desperate downward spiral, with no one willing to be held accountable for the manifest deficiencies of the NHS.

Government by special adviser is no way to run a country, though you might wonder what’s so special about their advice given the crisis in so many of our public services.

Scotland is crying out for exactly the sort of change that will ‘rattle’ SNP functionaries but it’s nowhere on the horizon.

The only ‘blue-sky thinking’ offered by the SNP is yet more costly rumination about another independence referendum.

Many hours have been wasted by those wearied civil servants, living in fear of seemingly all-powerful SNP strategists, drawing up plans for a parallel universe.

As we reported last week, Mr Swinney’s £30,000 independence relaunch was a humiliating flop, with as few as 28 people bothering to read the Fresh Start With Independence paper on some days.