The Third Parliament was an exercise in democracy which had never before been tried in Scotland, and only very rarely in any other western democracy. Minority governments are inherently unstable in a Westminster-style system: the last time it was tried in the United Kingdom, four decades ago, it lasted a mere seven months before the prime minister went back to the country to seek an extended mandate, which he achieved - a majority of three - before that, too, was whittled away as a result of deaths, resignations, and the failure of the confidence and supply agreement between the Liberal Party and Labour known as the Lib/Lab Pact.
John Major ran a similar minority government between 1996 and 1997: when he went back to the country to seek a renewed mandate, the electorate's answer to the old Tory question who governs Britain? was 'not you, matey'.
The failure of the Lib/Lab Pact led directly to Liberal MPs voting en bloc in favour of a No Confidence motion, brought by the Opposition leader, Margaret Thatcher. The SNP MPs voted against the government that night, which fell by a single vote. Had Labour MP Alfred Broughton voted with the Labour government, Jim Callaghan would have been saved by the Speaker's casting vote.
The fall of Callaghan's minority government was followed by a mandatory General Election in May 1979 instead of the scheduled election, which had to be called an absolute maximum of 160 days later.
In the schizophrenic and often borderline-psychotic world of Scottish Labour, the SNP voting against Callaghan's minority government has been transformed into 'the SNP voted to bring in Thatcher'.
Of course, it did nothing of the sort. Not only the SNP, but Parliament as a whole had no confidence in Callaghan's government, which had taken over halfway through Harold Wilson's term without asking the permission of the country. Indeed, Callaghan barely had any confidence in his own premiership, telling his Cabinet 'if I was a young man, I should emigrate'. Even the Labour Party had no confidence in Callaghan as prime minister: he was elected leader despite coming second in the first ballot, with only 26,8% of Labour MPs voting for him to be prime minister.
Callaghan had lost the support of the left some time before, massively cutting public spending and laying the groundwork for Thatcher's monetarist policies and, of course, the trade unions also lost confidence in his premiership as he forced them into the Winter of Discontent, frankly admitting in later years 'I let the country down'. Callaghan himself admitted that he himself had caused his downfall by shying away from calling an election in 1978, which was to have echoes three decades later when Gordon Brown - a similarly unelected prime minister - also shat it before losing in spectacular fashion the next year.
However, in the tortured, crazed weirdness of the Scottish Labour Party, none of this matters. In their fevered minds, the complex web of events which led to the collapse of the government was down to one single thing: the SNP brought down a Labour government and gave us Thatcher.
Certainly, if the SNP had voted with the government - a government, incidentally, which had just overturned the result of a Yes vote in the devolution referendum months earlier in favour of retaining direct rule from London - Callaghan would have survived for another few weeks. That's not in doubt. But Labour mythologise this into a lunatic dolchstoßlegende in which Alex Salmond, cackling maniacally as he stroked a white cat on his lap, personally defenestrated a Labour prime minister and equally personally installed Margaret Thatcher in Number 10.
This is nonsense, of course. As I show above, at the very most, the SNP voting alongside the government would have caused the election to have been delayed for 160 days at the latest, giving another 130 days of a Labour government. It is almost certain that it would not have lasted that long.
But Labour want the SNP to be the Tories' little helpers. In a way, they need them to be the Tories' little helpers. Perhaps it helps them to black out the taint to their party of their lengthy partnership with the Tories and their three-year campaign for the principle that the Conservative Party has the right to rule Scotland even if Scotland elects no Tory MPs.
Labour then use the second part of their fantasy - a very recently invented tale that the SNP was in coalition with the Tories during the Third Parliament.
This would be news to the Tories, who in fact voted more often with Labour in the Third Parliament than they did with the government, including when the Unionist parties united to force the disastrous Edinburgh Trams project through despite the opposition of the government. How many nurses and teachers could have been funded for the money Labour and the Tories coalesced to waste?
It is the stench of their collaboration with the Tories which force Labour to do this: put simply, they are rightly ashamed of what they did. They are ashamed that Scottish Labour councils were the most enthusiastic of all when it came to implementing Thatcher's hated Poll Tax, and that Scottish Labour councils were the most enthusiastic of all when it came to implementing Cameron's hated Bedroom Tax. It was Labour councils who got their thugs to kick down the doors of those who refused to pay the Poll Tax and sold families' property on the street. It was Labour councils who evicted Bedroom Tax victims with sheer glee.
It is the Labour Party who are in coalition with their Tory friends in a quarter of all Scottish councils. It is the Labour Party who have spent 13% of their entire time in government in Westminster in coalition with their Tory friends.
All one needs to do is look at the parties. Any of you who have ever been to a referendum or election count will know that the shiny, suited and booted, middle-class Labour and Tory activists are distinguishable from each other only by the colours of their rosettes. Nobody who attended a referendum count will forget the sight of those suited, well-fed, rosy-cheeked, exclusively middle-class Labour and Tory activists hugging each other with delight. They fit in well together. They campaigned together. They have been hand-in-glove for so long, with Labour doing the bidding of the Tories, that they have become mirror images of each other.
Scottish Labour needs to tell their Big Lie because they simply can't face up to the truth: that since Thatcher took over as prime minister, Labour councils did her bidding, Labour MSPs vote with Tory MSPs 90% of the time, and Labour activists happily collected data during the referendum to be handed over to the Tories for the purposes of winning Tory councillors, MPs and MSPs at election time.
Labour need to accuse the SNP of being Tartan Tories because they just can't face up to the truth: it's Labour who are the Tartan Tories.
There are 127 days until the next General Election. Three days less than the maximum lifetime of Jim Callaghan's government if it hadn't collapsed. It's not a long time, is it?
Yet Jim Murphy, the leader of the Labour Party in Scotland, has consistently refused to rule out Scottish Labour MPs going into a Grand Coalition with the Tories again. The SNP has explicitly ruled out a deal with the Tories. That Labour refuses to signals that the real Tartan Tories - the Labour Party - are preparing to be the same Tory lapdogs they've always been.