Jeremy Corbyn

To the Liberal Democrat campaign launch, then, in a small room all of 50 yards away from the House of Commons.

Britain’s third party has been through a radical reinvention in the last few months, from which it has now emerged as a pioneering rehab clinic offering a brutal treatment programme for MPs suffering Brexit-related political PTSD.

Only the Lib Dems are offering the full Brexit cold turkey. No customs union, no “strong single-market deal”, no second referendum, no methadone, no Tramadol.  The Revoke and Remain programme is savage, inhumane almost. Here they come to renounce their past, to come together and say “enough, no more” to the terrible men that have harmed them — specifically Boris Johnson and Jeremy Corbyn.

They are a mutual support group for disparate men and women who have only one thing in common – they will not have their lives controlled by Brexit anymore.

It takes courage, and it’s not cheap either. The entrance fee for most will in all likelihood be the loss of their main job. But they all seem to think it’s a price worth paying.

It’s a bizarre world in there. Standing at the urinals, you might find Sam Gyimah, making anxious small talk with an activist who’s dedicated his whole life to fighting the party for which Gyimah was an MP all of six weeks ago.

In the front row, waiting for the leader’s speech, you might spot Alistair Carmichael, a Lib Dem MP for fully 18 years. He thought he bagged a safe seat, then Chuka Umunna walked in and he found himself shunted back a row.

You might find Phillip Lee, looking a touch on the sheepish side. He was also a Tory until his defection two months ago, whereupon he was handed arguably the party’s most challenging brief, as the Lib Dems’ official spokesperson on why Phillip Lee abstained on the gay marriage vote in 2013.

If you look hard enough, you’ll even spot Luciana Berger standing at the lectern, introducing her party leader, a sight very similar to the one nine months ago, when she stood at a lectern launching a new political party which she has now left.

Still, in the hideous hall of mirrors that is British politics, this is probably the side you want to be on.

The reflection is less disfigured over here.

While Tory and Labour are purging their parties of the impure and fighting to suppress the varying absurdities and dishonesties of their Brexit plans and positions, the Lib Dems are an absurd thing to look at but at least they’re telling the truth.

They are not actively corrosive to listen to, and that must count for something. They hate Brexit. They’ll just get rid of it.

When group-therapy leader Jo Swinson eventually swept onto the stage, her orange dress a studied nod to the colour you’re most likely to get if you mix yellow, blue and red, she could hardly have been clearer.  “Get Brexit done. Get Brexit sorted,” she said, which are the Tory and Labour election slogans and both demonstrably absurd. “Red or blue. It’s all the same. It’s all Brexit.”

Which it certainly is. The position is a touch tricky, however. Her problem with Corbyn is that he won’t even tell you what he thinks about Brexit. A vote for Corbyn is a vote for a second referendum in which the actual prime minister – Corbyn – won’t tell you which side he’ll be on, if any.

On at least four occasions, she “categorically” ruled out any sort of deal that would use “Liberal Democrat votes to put Jeremy Corbyn in Downing Street”.

She didn’t rule out supporting Johnson, not as blatantly, anyway. But it’s absolutely clear that she won’t lend her party’s support to anything that enables Brexit.

So a vote for the Liberal Democrats, really, is a vote for whatever you want it to be. It might be a vote to stop Brexit but it might enable it. It might be a vote to stop Johnson, but you might end up getting him. It might be a vote to stop Corbyn, but you might end up getting him too.