On the penultimate day of their Autumn Conference yesterday, Liberal Democrat party members gathered in the Clyde auditorium of Glasgow’s SECC to vote on the pre-manifesto document. This document provides the bare bones structure for the eventual full manifesto, set to be published in Spring 2015 – shortly before the May General Election.

True to the party’s democratic nature, the pre-manifesto is drawn up not by leadership, but the Manifesto Working Group led by David Laws MP and academic Duncan Brack. This means that the leadership and the majority of Lib Dem Parliamentarians do not have input into the document. Additionally, the contents must be voted on by the wider party, meaning the core supporters must be convinced.

Five years on, the party has not had the foresight to avoid making the same mistake twice.

The difference this time is the leadership recognises the real mistake and will do everything in its power to mitigate the costs.

Over the last few days, one section of the pre-manifesto has created an unusual rift in the party. The document calls for no expansion of Heathrow, Stansted, Gatwick or any new airport in the Thames Estuary (Boris Island); and a promise of no net increase in runways across the entirety of the UK.

While popular with the Green Liberal Democrats and large swathes of the activist base, this position is dramatically out of step with what is expected to be the eventual findings of the Davies Commission. There has been considerable concern about the passage from party leadership and Parliamentarians since publication.

In an attempt to solve the problem, Stephen Gilbert MP and Lorely Burt MP, PPS to Chief Secretary to the Treasury Danny Alexander MP, tabled an amendment to the pre-manifesto that removed the blanket opposition. The amendment slightly altered the wording of the particular passage in question to create an exemption for expansion at Gatwick.

The pre-vote debate concluded with a resounding defence of the amendment from Gilbert followed by a withering indictment of the amendment by Brack. Despite Gilbert’s attempts, Brack had the pulse of the room and the assembled voting members of the Liberal Democrats swiftly defeated the amendment. It was decided that the original wording creating blanket opposition to airport expansion in the South East would remain in the pre-manifesto, and therefore, the eventual manifesto.

This has put the Lib Dem leadership in an awkward position: the Davies Commission will recommend airport expansion of some sort – while the location of such extra capacity is still uncertain, the need for spare capacity is not. Both Labour and the Conservatives are behind Davies with both supporting expansion.

This means that should the Lib Dems find themselves as minority partners in coalition from 2015, airport expansion will happen despite the party’s manifesto pledge. The ingredients for ‘Tuition Fees 2.0’ are already in place and it is unlikely the party’s left-wing activist contingent would take a second betrayal lightly.

However party sources tell Cicero Elections that the lessons have been learnt from the first fiasco. The root of the problem last time has been identified as the sheer volume with which the candidates advertised the pledge.

The plan will be to make it clear that this airport policy is simply one of many, many manifesto policies. It is not a red line; it is not special. Downplay it at every opportunity. And when it eventually fails to be included in any coalition agreement, the leadership will simply point to X Conservative pledges that failed to make the cut and say: coalition is compromise.

The plan is not perfect. It will require gumption and patient repetition of those manifesto pledges that do make the cut. But it is the best that the party’s leadership can do at this point.

It is worth noting that in an informal straw poll taken by YouGov’s Peter Kellner of attendees at an Electoral Reform Society fringe found more Lib Dems believe making the tuition fee pledge in the first place – rather than reneging on the pledge – to be the party’s true mistake. Hindsight is, of course, 20/20.

Five years on, the party has not had the foresight to avoid making the same mistake twice. The difference this time is the leadership recognises the real mistake and will do everything in its power to mitigate the costs.