Did it all start with a Glasgow kiss?

The volatility in British politics that has left much of the nation bedazzled and bamboozled by the sheer speed and scale of change might have had its origins in a Commons bar sometime after 10pm on February 22 2012.

This was when Eric Joyce, the former MP for Falkirk, decided to lash out after having one too many.

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Declaring in the popular Strangers’ Bar: "There are too many f****** Tories in here!" he subsequently headbutted the mildly-mannered Conservative member for Pudsey in West Yorkshire, Stuart Andrew.

Apart from the fact this was the beginning of the end for Mr Joyce’s political career, it also led to a process in which Labour had to find a new candidate for the Falkirk constituency for the 2016 General Election.

This, of course, itself led onto an almighty row between Ed Miliband’s Labour Party and Unite with allegations made that the trade union, which just happens to be Labour’s biggest donor, was trying to “stitch up” the selection process; an allegation it strongly denied.

Nonetheless, the claims of entryism led onto Mr Miliband’s (in)famous decision to seek to change the rules on how the leader was elected.

In March 2014, a special conference changed the rules; out went the old electoral college in which parliamentarians, trade unionists and party members each had one third of the vote and in came one person one vote.

But crucially and in a bid to open up the process to a wider audience and “let people back into politics”, Mr Miliband promoted the move to enable Labour supporters to take part in a future leadership election. The cost was the price of a cup of coffee; just £3.

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This, of course, following Labour’s defeat in 2015 led to Jeremy Corbyn being elected the party’s new leader. While the Islington MP got just under 50 per cent support from Labour members and 58 per cent support from trade unionists, the backing from those registered supporters was a stonking 84 per cent.

Yet since winning the Labour crown 10 months ago, the party has been embroiled in an unsightly civil war; so much so that Mr Corbyn, on the back of a wave of shadow cabinet resignations, cannot fill his frontline at Westminster.

But the Labour collapse in the run-up to the EU referendum led to charges Mr Corbyn, who for most of his career has been an Outer, had been absent from the frontline as an Inner; that in those Labour heartlands of northern England and the Midlands were the Leave vote was strongest, he had failed to put the work in to save Britain’s membership of the EU.

The EU result has unleashed a political whirlwind, including the departure of David Cameron from and the arrival of Theresa May to No 10.

It has also breathed life into another political giant: Scottish independence.

While the UK as a whole voted for Brexit, Scotland voted for Remain, so we now have the governments in London and Edinburgh facing in completely opposite directions; not for the first time.

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The PM insists Brexit means Brexit while the FM declares, for Scotland, Remain means Remain. No 10 has made clear Mrs May believes the idea of Scotland remaining in the EU while the UK exits it, is “impracticable”.

So the political forces, unleashed by the butterfly effect four years ago in a Commons bar, have not ended yet. Some might think Mr Joyce has a lot to answer for. Others might raise a glass to him.