My prediction for the Makerfield By-election:
Labour will win. It won't be a 'landslide', but it won't be close either. Burnham will win comfortably by a few thousand votes.
Restore will probably take a fair cut of Reforms vote, but I'd be shocked if Restore gets anywhere near 10% of the vote, or if this will be the 'shock' that Rupert Lowe is claiming. I'm expecting they'll get around 5%. Despite the small vote share they will get, Lowe and Restore supporters will still spin the result as a huge victory for their first parliamentary candidate.
Restore will also probably claim that Reform is no longer up to the job. If they can't win a by-election against an incredibly unpopular Labour Party in a seat which was majority pro-brexit, then how can they possibly win the next general election? That'll be their spin, I suspect.
Next up will be the Manchester mayoral election. If Restore doesn't run a candidate there, then in my opinion that proves that their only objective was to hold back Reform and allow Burnham to become PM. I think Restore voters should seriously question Lowe's intentions if that is the case.
With Burnham out of the picture, Reform has a much better chance of winning the mayoral election. Green voters will probably vote tactically in Makerfield to let socialist Burnham win and to keep Reform out, but I doubt they'll hold back in the mayoral race.
I therefore expect a leadership bid to begin almost immediately. If Starmer is on his way out, then Labour has a better chance of retaining some voters for the mayoral election. Equally, if Labour wins the mayoral race with Starmer as leader then it may give him new ammunition to say his 'change' is working among voters, and it may be enough for him to cling on.
There's no downside for Burnham if he begins the leadership challenge early. If Labour loses, it's Starmers fault. If Labour wins it will be because he has given them new hope by beginning the bid.
They're my predictions. Labour wins Makerfield comfortably, a bit of a closer mayoral election because Greens will no longer tactically vote. Restore will spin the relatively small & underwhelming result positively for the party, even though we'll be about to get a much further left wing Prime Minister. Restore won't run a mayoral candidate or a candidate in the Aberdeen South by election, but their supporters won't care.
In about 36 hours we'll see how right I am.