We'll know soon enough whether the decision was a masterstroke or a misfire.
A frenetic six-week campaign will dominate airwaves in the UK – once again putting political battles front and center in a country fatigued by a turbulent stretch for the state.
If, as current polls indicate, the opposition Labour party triumph, it will finally bring down the curtain of a 14-year era of Conservative rule, ushering in a center-left government led by former barrister Keir Starmer.
Any other outcome would mean Sunak has orchestrated a shocking victory that even many in his own party believe is beyond reach – and would result in the Conservatives extending a political dynasty toward the two-decade mark.
Here are some key questions answered.
Why did Sunak call an election now – and is it a gamble?
Sunak was obliged to call an election by December and hold it by the following month, but until that deadline – five years on from the last vote – the decision of when to stage a poll is in the gift of the prime minister.
Sunak told journalists at a drinks reception in December that it would be in 2024, not January 2025, and has more recently said his "assumption" is that it would happen in the second half of the year – which 4 July is, just about.
But beyond those clues, he has been tight-lipped while he weighed his options – feeding frenzied speculation in Westminster for months.
The main problem facing him is that no good options existed. Sunak is down around 20 points in opinion polls, and that deficit hasn't budged all year.
The economy is gloomy, and one line of thinking among his aides is that waiting until October or November would give it time to settle.
But on the other hand, Sunak has placed much of his political capital into his pledge to stop small boat crossings to the UK by asylum seekers. He has recently passed a controversial law to process some claims in Rwanda, though nobody has yet been deported and further legal challenges may await the plan.
Meanwhile, the warmer summer months are expected to see a huge number of such journeys across the English Channel, hurting a major pillar of his campaign message.
Ultimately, hours after some rare good economic news – a healthy month-on-month reduction in the rate of inflation – Sunak decided that Wednesday was the least bad time to pull the trigger.
Who's expected to win?
The near-universal expectation is that Sunak's Conservative Party will lose the election.
Labour have been leading in general election opinion polls since late 2021, and that lead has been huge for the entirety of Sunak's premiership. They are around 20 points up on average, with the Tories often closer to third party challengers like Reform and the Liberal Democrats than they are to Labour.
When converted to a projection of seats in parliament, those figures indicate either a comfortable Labour win or a Labour win so huge it would spell a near-wipeout for the Conservatives.
The Conservative brand was damaged by Partygate and a number of other scandals that led to the demise of Boris Johnson's premiership, and then the shambolic six-week tenure of his successor Liz Truss, whose fiscal agenda sent markets into turmoil.
But for Sunak's team, some deeper numbers provide some comfort. While Keir Starmer leads Sunak in polling on the question of who would make a better prime minister, that lead is much smaller than the overall party voting gap – suggesting Sunak will seek to keep the focus on a "me versus him" message.
Some polling experts also suggested that recent local elections may indicate a slimmer Labour win than polling does, but it is notoriously difficult to extrapolate nationwide forecasts from local votes in only some parts of the country.
Sunak may also take heart from an unlikely source: the left-wing former Labour leader Jeremy Corbyn, who started the 2017 general election facing a similar deficit and eventually forced a hung parliament, in a narrow loss to Theresa May.
Nonetheless, Sunak hasn't been able to move the polls in his favor since he became leader – he has just six weeks left to do so to claim a stunning upset victory.
What happens next?
Party leaders are already on the campaign trail, but parliament has a few days to wrap up any pressing issues before it is officially dissolved, 25 days before polling day.
Once that happens, the parliament that was formed in the previous, 2019 general election ceases to exist – and all sitting lawmakers are no longer MPs.
Sunak's government will continue to run the country, albeit in a skeleton format.
The main priority for every party will be the weeks-long dash around the country, where party leaders will seek to be pictured knocking on doors, standing in hi-vis jackets and meeting members of the public.
A series of TV debates will likely be organized too, when Sunak and Starmer will go head-to-head.
Then on Thursday, July 4, Britons will vote between 7 a.m. and 10 p.m. local time, and as soon as polls close, votes will be counted. A winner is usually declared in the early hours of Friday morning.
Who is Keir Starmer?
Rishi Sunak's rival for power is Labour leader Keir Starmer, who is heavily favored to become Britain's new prime minister in July.
A former, well-respected human rights lawyer who then served as Britain's most senior prosecutor, Starmer came into politics late in life. He became a Labour MP in 2015 and less than five years later was the party's leader, following a stint as shadow Brexit Secretary during Britain's protracted exit from the European Union.
Starmer inherited a party reeling from its worst electoral defeat in generations, but he prioritized an overhaul of its culture – staring down left-wing supporters of former leader Jeremy Corbyn, and apologizing publicly for a long-running antisemitism scandal that had tainted the group's standing with the public.
He has attempted to lay claim to Britain's political center ground, and is described by his supporters as a principled, serious leader with a focus on tackling the systemic issues facing Britain. But his opponents, on both the left of his own party and the right of the political spectrum, say he lacks charisma and ideas, and charge that he has failed to set out an ambitious and broad vision for the nation.
Who else is standing?
Only Sunak or Starmer have a realistic chance of becoming prime minister, but their plans could be disrupted by a number of smaller parties.
Sunak is especially vulnerable to the success of the Reform Party – a right-wing group attempting to outflank him on immigration – and the Liberal Democrats, a centrist, pro-European group who have chipped away at Conservative support in affluent, southern parts of England.
Given Labour's standing in the polls, Starmer is more equipped to take the fight to other groups. North of the border, he will look to end the Scottish National Party (SNP)'s generation-long dominance at the ballot box, capitalizing on a rocky period in the party's recent history that has seen them replace two leaders in just over a year.
But he will need to be mindful of the Green Party, which has challenged him from the left and has attracted some younger liberal votes as a result.
In recent local elections, there was evidence too that Labour's stance on Israel's war against Hamas in Gaza had harmed the party in majority-Muslim areas.
How does voting work?
In the UK, voters don't elect a prime minister directly. Instead, they elect a member of parliament (MP) to represent their local constituency.
The leader of the party that wins a majority of the UK's 650 constituencies automatically becomes prime minister, and can form a government. That means 326 is the magic number for an overall majority.
If there's no majority, they need to look for help elsewhere, ruling as a minority government – as Theresa May did after a close 2017 result – or forming a coalition, as David Cameron did after 2010.
The monarch has an important role; King Charles III must approve the formation of a government, the decision to hold an election and the dissolution of parliament. But this is a formal role only; the King won't contradict his prime minister or overrule the results of an election.
What issues will decide the election?
The answer to that question will go some way in deciding the night's winner.
Labour will be keen to define the election as a referendum on 14 years of Conservative rule, seizing on public fatigue with a party that has produced five prime ministers in that span and overseen Brexit, a stuttering economy and a series of sleaze scandals.
In particular, Starmer will talk plenty about the cost of living hitting British families, and the state of the country's overstaffed and stretched National Health Service (NHS).
Sunak, by contrast, will want to focus on migration – his pledge to "Stop the Boats" hasn't yet worked, but his flagship Rwanda policy has at least become law. And he will attempt to convince voters that the economy has turned a corner, and can't risk a change in governance.
Early signs also show he is attempting to make the question of leadership central in voters' minds – highlighting his time as finance minister during the Covid-19 pandemic in his first speech, and criticizing Starmer's record.
CNN
