The Conservatives are facing yet another set of by-elections in February, with voters in Kingswood and Wellingborough set to pick their new MPs.
The contests follow the resignation of former minister Chris Skidmore in protest at the government’s watering down of green policies, and the ousting of Peter Bone over allegations of bullying and sexual misconduct.
But it is far from the first mid-term vote Rishi Sunak has faced since he took the keys to Number 10 at the end of 2022.
We look back at the by-elections that have taken place during his tenure, how they came about, and what the outcome was.
City of Chester – 1 December 2022
Rishi Sunak’s first by-election test as prime minister was also the first public vote since Boris Johnson and Liz Truss were forced out of Number 10.
The contest was triggered by the resignation of Christian Matheson, the Labour MP who was suspended the previous October after two allegations of sexual misconduct from a former staff member were upheld.
Labour comfortably won the by-election, with its candidate Samantha Dixon keeping hold of the seat with 17,309 votes, a 60.8% share and nearly 11,000 more than the Conservative candidate.
While Labour was expected to win the seat, which it has held uninterrupted since 2015, it represented the worst result for the Conservatives in Chester since 1832, with candidate Liz Wardlaw getting 6,335 votes or 22.4%.
Stretford and Urmston – 15 December 2022
A safe Labour seat in Greater Manchester, Stretford and Urmston has voted red since its creation in 1997, and former shadow education secretary Kate Green had been its MP since 2010.
But when Greater Manchester’s deputy mayor – and a former Stretford MP herself – Baroness Hughes, announced she was stepping back from the role, Ms Green was announced as her replacement, saying it was “the right time… to move on to new experiences and opportunities”.
She had been nominated by the region’s mayor, Andy Burnham, and Labour leader Sir Keir Starmer gave full-throated support to the shift in direction for the former member of his shadow cabinet.
After being approved by the police, fire and crime panel, Ms Green officially stepped down and a by-election was triggered in her constituency.
But it passed without much drama, with Labour’s candidate, Andrew Western, not only keeping hold of the seat, but increasing the majority to almost 70% of the vote.
West Lancashire – 9 February 2023
Labour held on to the seat of West Lancashire when a by-election was triggered by the resignation of the constituency MP Rosie Cooper, who went on to become the chair of the Mersey Care NHS Foundation Trust.
Ms Cooper, who was elected in 2005, was the victim of a plot to kill her by an alleged member of the banned neo-Nazi group National Action and admitted the stress of her ordeal had “taken its toll”.
Labour’s candidate, Ashley Dalton, retained the seat for the party and secured a majority of 8,326 over Conservative candidate Mike Prendergast, with a 10.52% swing from the Tories to Labour.
In her victory speech, she said the people of her constituency have spoken on “behalf of the country” and sent a message to the Conservative government that they “do not have confidence in them to govern or the prime minister to lead”.
Uxbridge and South Ruislip – 20 July 2023
Mr Sunak was able to buck the trend of Conservative defeats in by-elections with a win in Uxbridge that came off the back of anti-ULEZ feeling in Mr Johnson’s former constituency.
The vote in Uxbridge and South Ruislip was triggered after the former prime minister stood down as an MP shortly before it was recommended he be suspended for 90 days for his role in the partygate scandal during the COVID pandemic.
Conservative Steve Tuckwell, a local councillor, successfully kept hold of the seat with 13,965 votes to 13,470 for Labour and 526 for the Liberal Democrats – giving him a majority of 495.
Speaking after his victory was announced, Mr Tuckwell said Sadiq Khan “lost Labour this election” by rolling out his Ultra Low Emissions Zone to outer London boroughs.
ULEZ aims to tackle air pollution and congestion by charging cars that don’t meet emission standards £12.50 a day to drive on central London roads.
Following the defeat, splits emerged in Labour after party leader Sir Keir Starmer called on the London mayor to “reflect” on the policy, which was criticised for being introduced during a cost of living crisis.
But Mr Khan stood by it, saying: “It was a difficult decision to take. But just like nobody will accept drinking dirty water, why accept dirty air?”
Selby and Ainsty – 20 July 2023
Selby and Ainsty, the North Yorkshire seat that has been Conservative since it was created in 2010, turned red in the by-election that was held following the departure of the constituency MP Nigel Adams after he was snubbed for a peerage.
Mr Adams, a close ally of Boris Johnson, confirmed he was stepping down from the Commons with “immediate effect” last June, following the former prime minister and former culture secretary Nadine Dorries.
Both he and Ms Dorries had been tipped for peerages in Mr Johnson’s resignation honours but neither featured in the published list.
Mr Adams previously said he would quit at the next general election.
Labour overturned a Conservative majority of 20,137 – the largest majority reversed at a by-election – propelling 25-year-old Keir Mather into parliament.
Mr Mather won 16,456 votes, compared with the 12,295 cast for the Tory candidate Claire Holmes, giving Labour a majority of 4,161.
Speaking after his victory, Mr Mather said the Conservative government has “failed us” – and “now it’s time for a fresh start”.
“In a year’s time I believe we will be on the precipice of a Labour government,” he said. “Today we have made history.”
Somerton and Frome – 20 July 2023
This South West seat has switched hands over the years in a straight fight between the Conservatives and Liberal Democrats, but Tory MP David Warburton had comfortably held the constituency with over 50% of the vote since 2015.
However, a scandal uncovered by the Sunday Times led to him being suspended from his party and sitting as an independent for over a year, before eventually resigning from the Commons.
The newspaper reported allegations of sexual harassment – which Mr Warburton denied – and drug taking – which he later admitted to – and an investigation from parliament’s commissioner for standards, Daniel Greenberg, upheld three allegations of sexual misconduct.
But Mr Warburton claimed he had been denied a fair hearing, and resigned in protest at the 14-month investigation, which he said had “inflicted unimaginable and intolerable destruction on my family and on me”.
Two weeks later, an independent expert panel upheld his appeal, saying the probe into his conduct had been “materially flawed”. But by that point, he had left parliament and a by-election had been triggered.
The campaign was again a straight fight between the Tories and Lib Dems, with the latter facing a steep hill in overturning the 19,213 majority Mr Warburton had won in the 2019 election.
But local councillor and Lib Dem candidate Sarah Dyke managed to secure her own majority of 11,008 over her Tory rival, Faye Purbrick, and took the seat for her party.
Rutherglen and Hamilton West – 5 October 2023
The by-election in Rutherglen and Hamilton West was regarded as the first test for Labour against the SNP in Scotland, where it needs to pick up a significant number of seats if it is to win the next general election.
The contest was triggered following a successful recall petition to oust the SNP’s Margaret Ferrier, who was found to have breached COVID restrictions during lockdown in 2020.
Despite hanging on as an independent after the SNP removed the party whip, last June the Commons voted to suspend her for 30 days, triggering the recall petition that saw her lose her job.
Labour went on to triumph in the by-election, with its candidate Michael Shanks defeating the SNP’s Katy Loudon by 17,845 votes to 8,399 – a majority of 9,446 and a 20.36% swing from SNP to Scottish Labour.
Sir Keir celebrated the result as “seismic” for his party.
Speaking to Sky News after his win, Mr Shanks said: “There’s absolutely no doubt that this result shows that there’s no part of the United Kingdom that Labour can’t win.
“It’s been a long time in Scotland – Labour building back to a place where people can trust us again.”
Mid Bedfordshire – 19 October 2023
A true blue constituency since 1931, Mid Beds has always been considered a safe Conservative seat in the home counties.
But its controversial MP – and her controversial exit – led to quite the battle when a by-election came to town.
Former culture secretary Nadine Dorries won the seat in 2005 and had steadily increased her majority in the following years to around 60% of the vote.
But in June 2023, she announced she was resigning from the Commons with “immediate effect”.
Ms Dorries’ initial reasoning was around a “new life opening up” for her, including the birth of her granddaughter.
But in the weeks following, it emerged that she had expected to be included in Boris Johnson’s honours list to take a seat in the Lords, and when her name failed to appear, she placed the blame at the door of Rishi Sunak, claiming he had blocked her appointment.
It took her a total of 81 days from announcing her resignation to actually officially quitting the Commons.
Both Labour and the Lib Dems had their eyes set on her seat, and a fierce battle broke out between the parties – with accusations of personal attacks on candidates.
In fact, senior figures thought the nasty atmosphere between the rivals and a failure to approach the by-election tactically risked letting the Conservatives keep hold of the seat.
But come the night, it was Labour’s Alistair Strathern who won the contest, getting over 1,000 votes more than the Tories’ Festus Akinbusoye and more than 4,000 votes ahead of the Lib Dem Emma Holland-Lindsay.
Tamworth – 19 October 2023
This Midlands seat had been Conservative since the party took power in 2010, and after the Tory MP Chris Pincher secured over 66% of the vote in 2019, there wasn’t much fear it could change its allegiances.
But the behaviour of the MP not only led to a by-election in that seat, but the downfall of a prime minister.
Mr Pincher had been the deputy chief whip in Boris Johnson’s government but quit in the summer of 2022 after allegations he had groped two men at a London members club.
It took days for the then prime minister to bow to pressure to suspend him from the party, and when it emerged Mr Johnson had known about other allegations before appointing Mr Pincher, his party turned on him, eventually leading to his exit from Number 10.
Meanwhile, Mr Pincher continued to sit as an independent MP.
An investigation by parliament’s watchdog concluded his conduct had been “completely inappropriate, profoundly damaging to the individuals concerned, and represented an abuse of power”, with them recommending a suspension of eight weeks – a long enough penalty to trigger a recall petition in the constituency.
Mr Pincher appealed against the sanction, but the independent panel stood by it, and rather than face the possible recall petition, the former frontbencher resigned, saying he did not want his constituents to be “put through further uncertainty”.
After a campaign where accusations of sleaze were very prominent, Labour’s Sarah Edwards secured the party’s second win of the night, with the second biggest by-election swing from the Conservatives since 1945.