The bookies now think there's a higher chance that Boris Johnson could lose his seat – here's why

The polls have narrowed a bit in recent days but the bookies still think the Tories are nailed on to secure the majority they crave.

The commonly available best price of 4/9 on that outcome represents an implied probability of 69 per cent. You can easily find 2-1 on a hung parliament which represents grim news for the opposition parties if the oddsmakers have this one right.

It’s worth remembering, however, that a general election is made up of 650 constituencies. The outcome of some of them could have an outsized impact nationally.

One of the seats is Uxbridge & South Ruislip where the sitting MP is none other than Alexander Boris de Pfeffell Johnson. You might know him better by the first of his two middle names and as Britain’s current prime minister.

It’s a safe bet that he will hold his seat at 1/7. But he's facing an energetic local campaign to oust him in favour of challenger Ali Milani, a former president of Brunel University’s student union.

Milani was given an opening quote of 5-1 with Paddy Power but has been backed into 7-2. Before writing this piece I asked the bookie for the five biggest moves in its constituency markets. This was one of them.

Milani was born in Iran and is a practicing Muslim. As such, Johnson - accused of Islamophobia on numerous occasions - being turfed out of parliament by this new contender is just too precious. If I didn’t have a strict rule of never betting on markets in which I have a rooting interest for fear of jinxing the outcome, I’d be inclined to have a small wager for fun.

The bookie has now priced up all 650 constituency markets and it’s fair to say that some of them are about as interesting as spending a weekend filling in government forms.

Former junior minister Helen Grant would need the mother of all earthquakes to push her out of Maidstone & The Weald, for example. Her odds of holding the seat for the Tories stand at 1-200. A gentle bike ride will get her over the line.

Some much bigger names face a much tougher slog. Take Johnson’s Brexiteer BFF Dominic Raab, the current foreign secretary who’s hoping to retain the Remain stronghold of Esher & Walton, where he’s been enduring a decidedly rough ride at hustings events.

The Harry Dunn affair is dogging Raab’s campaign. And so it should, given his brutally callous attempt to justify the Foreign Office seeking costs from the late motorcyclist’s family. They are asking for a judicial review of the decision to grant diplomatic immunity to the American woman who mowed him down.

Raab is still odds on to retain a seat in true blue Surrey where they’d usually talk about weighing rather than counting Tory votes. But the Lib Dems are pushing hard and are rated a 5/2 chance to provide the election’s “Portillo moment”.

As for the four other biggest betting movers, the Liberal Democrats are making all the running in Richmond Park, where Sarah Olney is hoping to regain a seat she won in a previous by-election from Johnson’s fellow old Etonian, Zac Goldsmith. Olney’s odds have shortened from 2/5 to 1/4.

That mightn’t look like a big move, but it is. It takes a lot of money to move the needle at such short prices. The scale of the move becomes much clearer if you convert the prices into percentages. Odds of 2/5 represent an implied probability of 71.43 per cent. At 1/4 it’s 80 per cent, which is very encouraging for Olney if the market speaks truthfully.

Portsmouth South offers a more obviously eye catching move, with Liberal Democrat city council leader Gerald Vernon-Jackson surging in to 17/10 from an opening quote of 9/1.

What’s interesting about this constituency is that it is one of the “Unite to Remain” seats in which the Greens stood aside to give the Lib Dems a clear run. The Tories are still the favourites (evens) to gain it from incumbent MP Stephen Morgan, who won the seat for Labour for the first time in 2017. He’s a 3/1 shot in one of the election’s hotter betting heats.

In Hartlepool there’s been something of a betting plunge on a candidate representing the other side of the fault line in British politics - the Brexit Party’s Richard Tice. His odds are in to 5/2 from an opening quote of 8/1. It’s worth noting that 5/2 is the same odds of the Brexit Party winning just a single seat. However, Labour is still an odds on 4/5 in the Hartlepool vs Tice contest.

There’s better news for the Tories in Finchley & Golders Green, which rounds out the list of top movers. The Tories opened at 11/10, but are now priced at 8/15.

Incumbent Mike Freer is defending a majority of just 1,641 over Labour, which needs to make gains in London to offset likely losses elsewhere in the country. However, this is a seat in which the Jewish community is strongly represented and the betting markets suggest that Freer’s main challenger is now a Liberal Democrat in the former of Luciana Berger, the Jewish MP who quit Labour over the anti-semitism scandal that’s been dogging the party.

The Lib Dems weren’t all that far away from losing their deposit last time around, securing just 3,463 votes, good for 6.6 per cent. Berger is, however, popular locally and represents a 13/8 shot. Labour trails in third at 12/1.

Nationally, the betting markets aren’t at all cheerful for Jo Swinson’s party. Phil Fairclough, political trader at Sporting Index, says the party has “fallen off a cliff” with clients. The spread on Lib Dem seats started out at 46-50. It’s now down to 23-27. Fairclough says Swinson’s Question Time appearance further knocked sentiment towards the party.

“The market has been fairly static over the last 10 days. What was seen to have been a big push for Labour and Lib Dems just hasn’t materialised,” he said.