Nigel Farage has set his stamp on this election: his astute action, standing down 317 Brexit party candidates (one in every seat that voted Conservative in the last election), confirms the brutal binary choice between the newly merged Tory-Brexit friends-of-Trump party and a flaky progressive remain alliance. The old Conservative party is no more, morphing into the Brexit party, its moderates having fled.

Here’s the vital question: will the fragmented progressives resolve their differences in an equally ruthless pursuit of power? They only have until Thursday to set aside petty tribal differences and block Britain leaving the European Union in January, with no referendum, on the hardest of Brexit terms. Sadly, the answer is almost certainly no. Not enough progressive candidates will stand down – unless they are seized this week with sudden paroxysms of self-sacrifice in the cause of the greater good.

A vintage Farage reverse ferret as he forges a leave alliance all on his own Read more

The Liberal Democrat, Green and Plaid Cymru agreement not to compete in 60 seats is admirable – but that’s not nearly enough. As the two main parties fracture at the top, while fraying at the bottom, each relies on dragooning reluctant voters with the threat of the hated other. Labour’s obtuse refusal to stand down anywhere is a colossal stumbling block: its rule book prevents it, party chiefs say, though that rule-book is ignored whenever the ruling clique wants to impose a candidate against local wishes. (Look at the disgraceful way Sally Gimson, a fairly selected candidate in Bassetlaw, was ejected by head-office diktat in order to impose one of its own.)

If they were brave, honourable Labour candidates in unwinnable seats could “forget” to submit nomination papers this Thursday if another party stands a better chance of keeping a Tory out. Not in a month of Sundays.

However, it’s good to see some sensible Labour candidates avoiding campaigning in key Lib Dem seats. This weekend I joined a mass Labour canvass in Crawley, members swarming into Langley Green shopping parade from surrounding no-hoper Sussex seats.

Crawley should be a natural Labour homeland, theirs until 2010, missed last time by 2,457 votes. But deeper than that, as its candidate Peter Lamb reminded his visiting troops, this classic post-1945 Attlee new town owes its tree-lined spaciousness to the lost spirit of that great council-housebuilding era.

Five carloads came from Lewes alone – a good sign, as the delegation was led by Mark Perryman, editor of a just-published collection of pro-Corbynist essays – who are tactically campaigning in Labour’s Sussex target seats, Crawley, Hastings, East Worthing, where Labour can win. It was not always thus. Lewes used to be Lib Dem, the only hold-out in Tory East Sussex outside of Brighton, when Labour voters threw the Lib Dems their votes. But as elsewhere, outraged by Lib Dem collaboration in the austerity coalition, in 2015 they refused. Norman Baker lost the seat and his party failed again in 2017 to Maria Caulfield, an ERG-leaning fierce Brexiter who supports tougher abortion laws. This time Labour people look set to back the Lib Dem candidate, Oli Henman, to overturn a 5,508 majority.

Farage withdrawing his Lewes candidate yesterday may have made that harder, but the real local spoiler is the Greens, whose candidate Johnny Denis will not stand aside. “We’re not a disposable party,” he says. “We’re always seen as the party that stands down, when Labour never does. I was the one who stood down last time and we got nothing for it.” In normal times that might not be unreasonable, as Greens have done well on Lewes council, and standing down shrinks their national vote. But the overwhelming local reckoning is that the Lib Dems are far better at winning over soft-Tory remain votes in the surrounding towns and villages. What, I ask Denis, will he feel if the Tory Brexiter wins this seat because of the split progressive vote? “I’d be disappointed, but in the bigger picture I don’t think it will make a difference as the Tories won’t get a majority.”

Brexit party will not contest 317 Tory-won seats, Farage says Read more

That’s the way it is in too many seats, all over the country (though the Greens have stepped aside in Chingford, to help the Labour candidate’s attempt to unseat Iain Duncan Smith). Of course people in Lewes should be free to vote Green or Labour, and standing down takes away democratic choice. But the real choice-killer is an electoral system that forces wise progressives to cast a nose peg vote for whichever local remainer has the best chance. The refusal of Labour and many other politicians to stand aside looks even worse after Farage’s move today to boost Boris Johnson.

Persuading at least 30% of voters nationally to vote tactically is an uphill task, made harder by three competing tactical vote sites that differ on a few seats. However, in a week or two a more reliable analysis of those contested constituencies is due.

The best hope is that this could be the last ever election fought on the abominable first-past-the-post system: if the Tory-Brexit party fails to win, any alliance of the rest could lead to a proportional system. The Lib Dems, scarred by their coalition agreement with the Tories, won’t be so dumb as to settle for anything less this time. The great majority of Labour members, including John McDonnell and Keir Starmer, strongly back reform.

Out in Crawley, in these early skirmishes – before voters are focusing and before manifestos crystalise cut-through messages – door-knocking tells you as little as the variable polls. You can cherry-pick the occasional “Yes, definitely, always Labour” or the “No, don’t like your leader” comments, along with randomly eccentric replies, though it’s worth noting how Brexit gets no spontaneous mention. Reminded what austerity has done here – the lost children’s centres, threadbare NHS and benefit hardships – people do respond. But don’t believe anyone who claims to know which way the wind is blowing.

• Polly Toynbee is a Guardian columnist

• This article was amended on 12 November 2019. An earlier version incorrectly stated that Mark Perryman was backing the Liberal Democrats to win in Lewes. This has been corrected.