Their targets are totally different
For all the talk of some sort of arrangement between LAB and the LDs the electoral reality is that both parties will broadly be targeting very different sorts of seats at the next election with very little overlap.
Because of the need to focus resources on seats they think they can win it is highly likely that both parties will be running almost token campaigns elsewhere. Sure candidates will be on the ballot but there will be next to no central office support, funding or VIP visits.
I have just picked up the pre-Christmas interview with Keir Starmer in the Times in which has been interpreted as there being a sort of arrangement with the Liberal Democrats but which isn’t.
The only problem I can foresee is if the LDs see potential in a North Shropshire type seat where they think they can win from third. For there is little doubt, as the December by-elections have shown, is that in certain seats Davey’s party is able in a by-election to attract former CON voters on a scale that Labour would find difficult.
None of this is the subject of any agreement but will be understood as being the right thing to do between the two parties.
All this is going to make the Tory defence that much harder.