A few weeks ago I tipped the Tories to hold North Shropshire at 2/5. Since then, everything which could go wrong has gone wrong for them and 7/4 is available from two bookies (at time of writing on Friday night). Suffice to say I wouldn’t place my 2/5 bets now. But I am about to advise you to back the Tories at current odds.

The core challenge in political betting, in my view, is separating emotion from prediction. Most obviously this relates to being able to bet on results you don’t want to happen. Another aspect is ensuring you don’t chase losses or conversely get gunshy after a bad bet.

At some bookies, traders aren’t even allowed to see the profit/loss position on a market when they adjust the odds so they can’t let it influence their judgement. Here’s why, if I were placing my first bet on North Shropshire, I’d be backing the Tories.

Being the devil you know

The biggest card the Tories have to play in North Shropshire is that, demographically, it reflects their core vote fairly well. It is older, whiter, and more Leave-voting than the country at large. Their biggest problem is that it is exactly those voters who are currently shifting to ‘Don’t Know’ in national polls causing Labour leads.

There is a big ray of sunshine for the party, however: Those voters have not yet found an alternative they like. Nationally we are not seeing massive shifts to Labour (who are rising, but not nearly as much as the Tories are falling) but rather a fair amount of Tory voters now saying they wouldn’t vote at all or can’t say who they’d support.

This should help the Tories hold their vote together a bit more effectively, a challenge helped by their main opposition. Older, whiter, Leavers may not be thrilled with the government right now: But they dislike the Lib Dems much more generally speaking.

Bexley wasn’t too bad

The past few decades have several by-election precedents the Lib Dems are hoping to repeat. In Christchurch, 1993, a lead of 40% at the General Election was swept away by a 35% swing to the Lib Dems (North Shropshire would take 27%). Bermondsey, Brent East, Newbury, and Orpington are also spoken of fondly by activists.

But the past few weeks are much more encouraging for the government. Bexley and Old Sidcup took place before ‘Partygate’, but it was only last week and Labour were virtually tied in the polls already. The Tory vote share fell only 13%. Another result even vaguely like that and a hold is more or less assured.

It is true the Lib Dems are better at big by-election swings than Labour, just look at Chesham & Amersham. But even there they failed to get a swing large enough to win from this far back. And in much more fertile territory. Winning from 3^rd is particularly rare, and might complicate that crucial tactical squeeze message.

Caution is advised

I do need to acknowledge the other side of this argument. In the past, really big swings have often been driven by extremely efficient tactical voting by the opposition. Just look at Bermondsey in 1983, the greatest swing in history, where the Tories went from 25% to almost losing their deposit. And in Winchester, 1997, Labour were squeezed to under 2% despite their national popularity.

The Tories also have problems on their right flank. Richard Tice’s 6.6% in Bexley and Old Sidcup wasn’t particularly impressive, but even that level of support would be votes the Tories might not be able to afford losing this time – and we have seen Reform UK polling better nationally this week than before.

For my mind, the value is still with the Tories due simply to the scale of the challenge and the imperfect ground for the challengers. But the political situation is unusually fluid right now, and anything from a comfortable Tory hold to a stunning defeat are perfectly possible. I’d keep my stakes low if entering the market now, but I’d enter on the blue side of the bet.

Pip Moss posts on Political Betting as Quincel. He has bets on the Tories winning North Shropshire at roughly 4/11 and just under 7/4. You can follow him on Twitter at @PipsFunFacts