It's early 1981, 25th January 1981 to be precise. The Labour Party has had a new leader, in the form of Michael Foot for a number of months, and he has subsequently shifted the party to the left. Foot is an anti-nuclear leader, and was party of Labour's 1945 landslide intake. Some of his PLP colleagues are restless.
The frustration reaches fever pitch. It suddenly boils over and then they break cover. Four Labour MPs, (Shirley Williams, David Owen, Roy Jenkins and Bill Rodgers), the so-called Gang of Four announce they are leaving the Labour Party, to establish the "Council for Social Democracy".
Two months later, this unusual organisation blossoms into the Social Democratic Party, or SDP. This pivotal moment in postwar British politics comes to be known as the Limehouse Declaration.
Implications of a Labour split
The Limehouse Declaration was a brave move, but not necessarily a wise one, with hindsight. Unshackled by the strains of being led by a disagreeable leader, the Gang of Four seemed to have managed to fill a perceived vacuum in British politics.
Somewhere, amid all the Tory-led calls for spending cuts galore, and the Labour-led calls to scrap Trident, they believed there was a neglected third way.
The SDP soon realised, however, that it lacked the sheer magnetism of a pre-established party, and so it was only natural for the SDP to form an alliance with the Liberal Party, from days of old.
The Liberals had once been a party of government (in the Victorian/Edwardian era), but by 1981, they were a diminished force.
Labour had absorbed much of their voter base by this point. Then along came the SDP. The two parties got cosy, but it took until 1988 for a merger to take place.
At last, the two parties could run for office under a single leader, and they became known hereafter as the Liberal Democrats.
The problem is that the SDP/Liberal alliance failed to inspire much enthusiasm, and when Labour eventually shifted to the centre under Neil Kinnock, they actually ended up splitting the leftist/centre left vote. As a result, you could argue that the Thatcher era was a product of the left/centre left not getting its act together.
But what about now?
At present, it is fair to say that there is some sort of residual restlessness within the Labour Party, following the election of new leader Jeremy Corbyn. Former Shadow Cabinet minister Rachel Reeves used an interview on today's Daily Politics to claim that Mr Corbyn was guilty of a "dereliction of duty".
Reeves also claimed that Labour was making a mistake, in shifting against Trident. In her view, "They [the party leadership] have opened up this issue of Trident. There wasn't an issue in the country".
Reeves simply doesn't believe the country is particularly anti-Trident, and that Labour is becoming too introverted; she is implying that it is choosing to talk about what it wants to talk about, which isn't the same thing as what the electorate are worried about.
Could there be a 1981-style split? It's the 35th anniversary of the Limehouse Declaration, but all we seem to be seeing is the occasional gossip about disquiet amongst PLP members.
This comes, along with hearsay about the possibility of some move against Mr Corbyn, but only if Labour peforms poorly in the local and mayoral elections in the spring.
Some of the gossip has implied that action against Mr Corbyn might not even take place until after the EU referendum, and we don't even know when that is going to take place!
Gossip is worth bearing in mind, but at present, it's just that; gossip, and as we know, gossip is cheap. Actions speak louder than words. The moderate movers and shakers are just talking at the moment.
Nothing concrete has been done by Labour moderates to depose Corbyn, but they seem to have learnt from past mistakes; now is no time for a new SDP.
At least not yet, that is. They are sitting tight, waiting for the next big gaffe. There may be many more, before they get the straw that breaks the camel's back.
It's a question of whether they take the gamble of cashing in now, and creating a new party, or sticking with what they know, and trying to influence proceedings from inside.
