The best betting apps expect Sir Keir Starmer to become the next UK prime minister and think Rishi Sunak has just a one-in-four chance of keeping his job after the next election.

What’s more, there is no fixed agreement across the markets on how likely Boris Johnson is to return to power.

The UK prime minister generally leads the party with the biggest number of seats in the House of Parliament. Right now that’s Sunak, who has a working majority of 64 Conservative MPs.However, the next UK election is expected to significantly shake up the numbers. 

UK betting sites believe Starmer’s Labour party will win a majority at the next election, and therefore their leader will become PM. So confident are some bookies that they’ve refused to budge on Starmer’s historically-low price for months. It means the Conservatives appear closer to losing power with every day that ticks by.

Yet the UK prime minister political betting odds also have to factor in the possibility of a mutiny against Sunak from his own MPs. This market won’t necessarily be settled at the next election, it may be done months before then.

Therefore the possibility of an alternative next prime minister – perhaps Johnson, or maybe one of Sunak’s ministers – remains.

How UK Prime Minister Betting Worksx

Choosing a UK prime minister isn’t like electing a president in the United States or France. The prime minister is simply the leader of the majority ruling party in the House of Commons, who seeks a mandate from the monarch to govern the country.

They can therefore be toppled. This is done either at a general election, at a snap general election, or through an insurrection in their own party.

Remarkably, just two UK prime ministers since Margaret Thatcher have initially risen to power via the ballot box. Gordon Brown, Theresa May, Boris Johnson, Liz Truss and now Sunak all landed the top job after ousting their party leaders.

That shows the weakness in the UK prime minister's betting markets. The bookies cannot simply offer odds on the next PM based on who will win the next election. They also have to take into account the possibility of a mutiny.

Here are the current odds on who will be the next prime minister. In Sunak’s case, he would win the market if he wins the next election:

Odds via Ladbrokes and accurate as of May 17, 2023

As you can see from the list, Starmer is the only non-Conservative figure in the running for the top job. After him, the bookmakers have a long list of Tories who could feasibly replace Sunak.Of course, they wouldn’t replace Sunak at an election. They’d replace him via a Conservative party vote only once the PM has been toppled.

Latest UK Prime Minister Odds Changes

And this leads to an interesting debate about the immediate future of the Tory party. 

The Conservatives have endured three prime ministers in the space of a year. Johnson’s premiership collapsed following a spate of sleaze scandals, Truss lasted 45 days before her economic plan forced ministers to oust her, and now Sunak has been left to pick up the pieces.

Sunak is polling 17 points behind Labour. The Conservatives are an electoral machine and have ditched their leaders before if they think they can’t win at the ballot box. It means there’s a very real possibility that Sunak could be ousted.

To do this there needs to be a swathe of resignations from within the Conservative Parliamentary Party, as happened to Johnson. Were Sunak to resign then a new leadership contest would begin, and a new prime minister would be voted in via the country’s 200,000 Conservative members.

It is this possibility that prevents the bookies from narrowing Starmer’s odds even further. After all, the Labour leader can only gain power at an election, while the other candidates can obtain the top job via other means.

Sunak’s odds haven’t improved for months – but there is an interesting lack of consistency among bookmakers when it comes to Johnson. It’s well known that the former PM would like another shot at the job and feels he was forced to quit office last summer, despite the sleaze scandals mounting against him.

Johnson is still an MP and could make a comeback if he sniffs an opportunity. Some bookmakers have him as short as 7.00 (+600) to be the next prime minister. Others have thrown his price out as wide as 17.00 (+1600).

That exposes not only the uncertainty around Johnson, but the market as a whole. And it’s therefore ripe for punters to take advantage of. Indeed, while most bets in this market have gone to Starmer (38%), the second-most are backing Johnson (20%). At such a varied price, bettors can lock in great odds in the hope Sunak’s premiership soon comes to an end.

Next Prime Minister Betting Predictions

Saying that, it appears as though the Tories will not be toppling their leader any time soon. The bookies reckon Sunak will see out 2023 and should make it to the next election. 

Right now, the ex-chancellor who once courted public popularity with his furlough scheme is the only horse the Tories are backing. Johnson is waiting in the wings but no-one quite knows if he is electorally viable anymore. The public grew sick of his sleaze and don’t forget in a hurry.

From a prediction perspective, it appears as though Starmer is on course for Downing Street. Even if Labour don’t win a majority it’s likely Starmer would be PM in a coalition government with the Lib Dems. Bettors have a choice. 

Stick with the low-odds Starmer and bank on there being no Tory rebellion against Sunak. Or back Johnson and wait for the drama to unfold in Westminster. Very few will back Sunak to win the next election.