One of the big promises of the Lib Dems general election campaign was that there would be “no deals, no coalitions”. However, now that Tim Farron has resigned as leader, it does leave room for the new leader of the party, whomever they may be, to reverse this decision.
The outline of such a deal would be pretty straightforward: no formal coalition, simply supply and confidence in return for single market membership. There is no way the Tories would go for it at the moment, namely because they do not want to seem like they are explicitly responsible for making a soft Brexit happen simply in order to cling to power. This is why other parties are being invited into the whole Brexit process – the point is, if we end up with a soft Brexit, even as a temporary deal, the Conservatives will want to spread the “blame” around. So doing a deal on this basis is out, and it’s the only basis upon which the Liberal Democrats could realistically proceed with such a thing.
However, that only pertains to the here and now. Who knows where we’ll be in a year’s time (who knows who will be prime minister by then), and there could be an opening that presents itself in which the Lib Dems could actually hold the balance of power in such a way as a demand for soft Brexit could be in play. If this was the case, I think the party should go for it. I don’t think the party’s core vote would mind a deal with the Tories if it managed to save single market membership, and the Lib Dems need to get out of the mindset that if they are somehow sufficiently leftie enough, the Left will re-embrace them (see Sheffield Hallam and Leeds North West if you don’t believe me).
I understand why the “no deals” pledge was made – to assure everyone that the Lib Dems would not jump into bed with the Tories again, and to assure centre-right Remainers that the party wouldn’t make Corbyn prime minister (that, by the way, is the deal that I think really would have been fatal for the Lib Dems to have made). But I really think the Lib Dems would be rewarded for making a difference if it arose – and I want to be clear, I don’t see a set of circumstances in which this will be case at present, but we live in very dynamic times. If the Lib Dems refused to make that sort of a deal to save the country, what then is the point of the party?