Alan Hayman was an SDP County Councillor in Essex in the 1980s, and stayed with the Owenite Social Democrats till they collapsed. 

At the age of 16, my son Gregory is too young to vote and has yet to join a political party. Meanwhile he follows politics from a distance with the same passion the Queen shows for horse-racing, and is generally a good judge of form. Accordingly, he responded quickly to the news that the next Labour leader might be Jeremy Corbyn (or Lenin’s Grandad, as he is affectionately known at our family meal-times). “Dad”, said Greg with the authority granted to the young, “it’s time to relaunch the SDP.”

I joined the Social Democrats as a founder member in 1981, hoping for a progressive but sensible party that would save Britain from perpetual Conservative government. Roy Jenkins seemed fit to lead the country without also taking Britain out of NATO and into the Warsaw Pact. All went well at first, with a string of by-election wins in partnership with the Liberals. But voters (and the commentariat) were puzzled by the need for two centre-left parties occupying the same political space. The outcome was the merger of the two Alliance parties to form the Liberal Democrats.

A small but determined band of Social Democrats led by Dr David Owen tried to carry on. Their SDP Mark 2 was a vulnerable craft, soon swamped by heavy political seas. Its swift descent to the seabed was hastened by the venomous hatred of the Liberal Democrats – then, as now, not as nice as they looked.

By contrast the SDP Mark 3 – or “New Labour” as it was branded by its founder, Tony Blair – was a roaring success. Rather than build a new party from scratch, Mr Blair sensibly salvaged the useful parts of the existing Labour Party and ignored or discarded the rest. Union money was supplanted by gifts from business, and the party conference became a glitzy rally for the leadership. Mr Blair himself rarely spoke or wrote about why he was a social democrat rather than a socialist. He knew that theological disputes and rivalries on the Left of politics interested very few voters. Also, he was busy winning three straight general elections.

The wheels came off the New Labour project when the money ran out. Social democracy does well when there is public funding to support an ever-bigger State sector, together with its employees and clients. Neither Mr Brown nor his hapless successor properly answered the question – how does Social Democracy build a better society if a world economic downturn brings austere financial times to the UK?

By contrast, Jeremy Corbyn’s answer is completely to reject the seductive charm of social democracy. Instead he hopes to dig up the bones of Old Labour, breath life into the corpse and hope it can lead Britain to a Better Yesterday.

Can – and should – the social democrats in Labour ranks respond with a breakaway SDP Mark 4, as they did in 1981?

Despite my son’s enthusiasm, I think the answer is no. The SDP Mark 1 was born when the UK’s political ecology was crying out for new life-forms. Today, the Greens, UKIP and the Scottish Nationalists provide a diverse range of alternative political homes. Disenchanted Labourites will also find that Mr Farron is ready to welcome them into the Liberal Democrats, with no need to swallow the contents of Nick Clegg’s Orange Book. And perhaps one or two might even make a harder journey across the floor of the Commons – to the Conservatives.