If Jeremy Corbyn is successful in his Labour leadership bid, despite Chuka Umunna's call for unity around a new leader, there will be calls for a breakaway. The way the other leadership candidates and Labour insiders are talking, it's as if a Corbyn victory will spell Armageddon for Labour - as Dan Hodges wrote just this week. Whether it's bluster or the real McCoy it's worth considering the options for potential Labour defectors. The recent electoral near annihilation of the Lib Dems should make wobbling Labour members think long and hard about the merits of tearing up their membership cards. And if they are looking to jump ship there is a question mark over whether the Lib Dems under Tim Farron offer defectors an appealing and distinctive enough alternative political home. While it has become a common refrain that two-party politics is at an end, begging the question why not form another breakaway movement in this age of multi-party politics, if Labour supporters are looking to put their social democratic principles into practise then the SDP's warning from history might make them think twice.
The Lib Dems were of course formed by the marriage of one of the oldest and one of the newest political movements in Britain in 1988 following the failure of both to achieve electoral success in the 1987 general election. However, some partners were more equal than others - recall Spitting Image's bruising satire on their uneasy alliance: 'from our side we'll take 'Social Democratic', and from your side, we'll take 'Party''. The SDP had broken away from the Labour Party in 1981 when the 'Gang of Four', Roy Jenkins, David Owen, Bill Rodgers and Shirley Williams, concerned with the lurch to the left of Labour under Michael Foot, broke away and formed their own left-centerist party. Labour under a Corbyn leadership would almost certainly suffer a similar lurch to the left. The question is, what options do those disenfranchised centerist Labour-ites have if they cannot stomach the newly Old Labour, and crucially do the Lib Dems offer defectors an attractive alternative?
Potential defectors broadly have three choices: grin and bear it and hope that Corbyn falls before too much damage is done, form a new SDP (preferably with a catchier name), or join the old SDP - the eviscerated Lib Dems under new leader, Tim Farron. Most will take the first option - either putting up with Corbyn, supporting him or waiting for the all-but-inevitable second leadership election in this parliament. The second option just seems unlikely - the devastation of Lib Dems sends a strong warning, and it's questionable whether a new political movement can really grow out of Labour - UKIP and SNP were single issue (or close to) parties that grew from grassroots dissatisfaction with the mainstream into fully fledged parties with wide appeal. It's the third choice - defection to the Lib Dems - that presents the most plausible and interesting option.
Yet, it also begs a fundamental question: if you are, for example, a disenfranchised Labour councillor would you move to a party led by Tim Farron, a distinctly left of centre leader with interventionist instincts who will probably take the party 'back' to the kind of political territory inhabited by Charles Kennedy? I can't see New Labourites seeing Farron as their White Knight.
That said, Tim Farron's plan to shift the Lib Dems back to the left is a job made that much harder if Corbyn gets the top opposition job. Is it possible that Farron might actually hold the centre-ground more than many of us have given him credit for? Will he capitalise on the potential to woo Labour members and even MPs into the Lib Dem fold? And if he does, won't he need to anchor his party to the centre / centre-left to most effectively entice the right of Labour away from the fold? The more you start to explore the permeations of this the more complex it gets, but one thing is clear: Tim Farron has the potential to position the Lib Dems as the natural home for disaffected Labour members - the question is whether and how he does this.
It may just be that the Lib Dems under Farron are not 'progressive' enough for the new Labour posse for whom a Corbyn victory is a political anathema. You might just wonder if Clegg had held on to his party's leadership whether he might have been better placed to siphon off the odd disgruntled labour defector. We'll never know.