Is there going to be a pro-Remain joint candidate in the Peterborough by-election? Change UK’s Anna Soubry has publicly confirmed rumours that discussions are ongoing between her party, the Liberal Democrats and the Greens, adding for good measure “we are again putting country before party”.

As I explain in greater detail here, from Change’s perspective, this is all about finessing the outcome of the local elections. Plan A – to squeeze out the Liberal Democrats – doesn’t look seaworthy anymore, and everyone accepts that it is Change UK who have received the worst press coverage as a result of the failure to agree some kind of joint co-operation effort for the looming European elections.

From a Liberal Democrat and a Green perspective, a joint ticket wouldn’t be the worst thing in the world: neither party is particularly strong in Peterborough, nor have they ever been. Even in the Liberal Democrat wave years of 2005 and 2010 they were way off the pace, while the Greens did no better in 2015, a year when they did fairly well by taking former Liberal Democrat voters in most cities. They each won one councillor apiece in last week's local elections: not a fantastic launchpad to break up decades of two-party duopoly in a by-election.

Frankly it’s a contest in which you wouldn’t be shocked if both, or either party were to lose their deposit, and in my view Change UK are taking a big risk in standing or making this much noise about a joint candidacy. This is the kind of place they really need to be winning if their argument that they can win in places that the Liberal Democrats and Greens cannot reach is to have any real-world application.

To run so soon after their bungled European rollout, with their party’s identity and positions largely unknown, a Change candidacy looks to me to be a recipe for a very painful defeat. From a Liberal Democrat and Green perspective, joint candidacy between the three parties simply removes the Liberal Democrats and Greens from an election they are not going to win; and several of their gains last week were the result of discreet cooperation between the two parties at a local level.

But for any joint candidacy to happen it has to be agreed by the local parties – the Liberal Democrats and Greens are both highly democratic organisations – and both parties have selected already. Soubry’s tweet has left people feeling bruised in both other parties. and has decreased the chances of it happening.

For Change UK that may be a win in and of itself: it can avoid a by-election that could prove fatal while presenting it as an example of doing politics differently. But it comes at a cost: any co-operation with the Liberal Democrats is going to be reliant not just on the relationships they build at the top, but the feelings of Liberal Democrat activists: and the mood among the party rank-and-file towards Change UK is souring fast.