Corbyn refuses to give as well as take in Remain constituencies – that’s why voters still need the Lib Dems

In the absence of long overdue reform of the voting system, tactical voting based on up-to-date information is the best mechanism we have for individual voters to make a difference on Brexit

Over the last few days I have had indignant messages from acquaintances within the Remain movement telling me to support the Lib Dem candidate in Canterbury who had “done the decent thing” and stood aside for the sitting Remainer Labour MP. The same people were taken aback when I asked how many Labour candidates were standing aside for Lib Dems in, say, St Albans or Cheadle or Wells or Wimbledon.

What those fulminating at Labour and the Lib Dems for not standing down in each other’s favour must remember is that the parties do not own the votes of their supporters. Voters cannot be directed, and while some may shift as expected, Lib Dem support is built from both Conservative and Labour Remainers. The former group is not inclined to vote for Jeremy Corbyn’s party in any circumstances, so the assumption that every Lib Dem vote would be added to the Labour pile is overly optimistic.

I suggested that there is a simple remedy for voters who, rightly, regard opposition to Brexit as an issue which transcends tribal loyalties. It is called tactical voting. There are dozens of seats where a Johnson Conservative can be defeated by Remain candidates from one of Labour, the Lib Dems, Greens or an Independent. But voters will have to make some good judgements.

In some seats it is obvious how to use a vote most effectively. But where calculations are more complex, there are good websites (such as that designed by Best for Britain) which can give advice based on constituency-level survey data. These reflect the big shifts in seats like Kensington, Cites of London and Westminster, and Finchley and Golders Green where Labour have fallen to third place.

In the absence of long overdue reform of the voting system, tactical voting based on up-to-date information is the best mechanism we have for individual voters to make a difference.

Meanwhile, many voters insist that they must vote for Boris or Jeremy or Jo regardless of which constituency they are in, either because they don’t fully appreciate the distortions of our first-past-the-post system, or because it doesn’t matter to them. For some voters, casting a ballot isn’t about achieving a result but making a personal statement. Others have what may seem strange priorities but which are nonetheless important to them.

I spent an inordinate amount of time last week on the doorstep with a man claiming to speak for his (large) family who believed that Brexit was trivial as an election issue compared to the local council’s proposed 20mph speed limit. The story illustrates, all too prosaically, why a general election is so much less satisfactory than a confirmatory referendum would have been for resolving the Brexit issue.

Because of those limitations, and because the Remain/Brexit issue is so important, the Lib Dems are indeed working with other parties. Alongside the Greens and Plaid Cymru, my party has reached an agreement covering 60 seats, which has been extended unilaterally to support some independents like Dominic Grieve.

Having helped to launch this alliance, I don’t underestimate the achievement or the difficulty in getting there. At the 2017 general election, I reached a localised agreement covering three seats which met the interests of Lib Dems and Greens. It was carried forward into local government elections the following year but the Lib Dems’ governing national body spent much time agonising over it. A lot of trust is required as well as common ground.

In consequence, the Remainer alliance is still incomplete. It rests on reciprocity. There are areas where big egos or ideological fervour or sheer bloody-mindedness still get in the way of seemingly obvious agreements. The Lib Dem candidate in Wokingham, who otherwise has an excellent chance of defeating the leading Brexiteer and climate change denier, John Redwood, is exasperated by having to divert effort to fight off a spirited but hopeless Green campaign. But, as far as it goes, the alliance is a big step forward.

The obvious question is why it doesn’t include Labour, or a bloc of Labour MPs, who identify with Remain rather more than the ambiguous Labour leadership. Notwithstanding the inability of parties to gift “their” voters to others, there are probably a couple of dozen seats where the absence of a Labour candidate would deliver a Conservative seat to the Lib Dems; there are certainly Labour-held seats, with good Remainer MPs, where the intervention of a Lib Dem and/or Green might well let in the Conservative. The mutual self-interest is, or seems, clear.

Yet it is Labour which has emphatically ruled out the idea of an electoral pact with “give” on their side as well as “take”. They even insist on opposing Caroline Lucas in Brighton, which baffles and infuriates Remainers, socialists and greens alike. Where the Lib Dems are concerned, fear and loathing dominates on both sides of the relationship. A liberal party is naturally suspicious of Corbyn’s retreat into hazy romanticism about Latin American socialism, and Labour cannot see past the 2010 coalition government.

Still, if Labour were serious about winning over Remainers they would have put the Lib Dems on the spot offering a seat-sharing arrangement. The Lib Dems know that anything which suggested collusion with Corbyn’s Labour would do serious damage among the Tory-leaning Remainers who plan to switch to them. Refusing such cooperation would be equally damaging among former Labour voters who had recently switched.

Fortunately for the Liberal Democrats, Labour is far too politically tribal, cautious and flat-footed to do anything so smart. Under the surface bluster, I doubt that Corbyn’s team is truly serious about winning. The half-baked proposal for nationalised, free broadband suggests they are not. Perpetual protest and opposition suits them better.

Nonetheless, Remainers should not despair. The Johnson dream of a united Leave campaign is not fully realised, since Nigel Farage’s compulsive need to be recognised will continue to undermine Tory efforts to gain new seats. Meanwhile though nominations have closed, and no candidate can now pull out of the race, they can all be sensible about how they use their time.

Where a candidate knows themselves to be a “no hope”, they should quietly disappear to help their party in another constituency and make positive noises about the good sense of tactical voting. Brexit remains on the brink in this election: with self-discipline and good sense, there is still every chance to stop it.

Sir Vince Cable was leader of the Liberal Democrats between 2017-2019 and is a former secretary of state for business, innovation and skills