Labour’s apparent impending victory in the General Election would bring down the curtain on 14 years of Conservative-led government at Westminster.
We look back at how the past decade-and-a-half unfolded.
– 2010 to 2015: The coalition years
The general election of May 6 2010 brought to an end Labour’s run of three straight victories but failed to deliver the outright victory the Tories were hoping for.
With his party 20 seats short of an overall majority, the Conservative leader David Cameron made “a big, open and comprehensive offer” to the third-placed Liberal Democrats to work together in government.
After five days of intensive talks, Mr Cameron emerged to announce that the two parties had agreed to form the UK’s first coalition government since the Second World War, with Lib Dem leader Nick Clegg serving as deputy prime minister.
The years that followed were dominated by the fallout from the 2008 global financial collapse which saw the Labour government of Gordon Brown pour tens of billions of pounds into bailing out the banks to prevent a complete implosion of the financial system.
In the course of the parliament, Mr Cameron and chancellor George Osborne slashed spending by around £100 billion in “austerity” cuts as they sought to rebuild the shattered public finances.
Despite the economic constraints, the government nevertheless pushed through major – and highly controversial – reforms to the NHS and benefits system, with the introduction of Universal Credit, while privatising Royal Mail.
In a surprise move, it introduced legislation to enable same-sex marriage, which had not been in the Tories’ general election manifesto and only passed with Labour support, with a majority of Conservative MPs either voting against it or abstaining.
In 2011, Mr Cameron announced that he was setting up the Leveson inquiry into press standards following claims that private detectives working for the News of the World had hacked the phone of murdered schoolgirl Milly Dowler.
The prime minister, who had previously hired the paper’s former editor Andy Coulson as his director of communications, was among those called to give evidence, while Mr Coulson subsequently went to prison.
Overseas, he joined France in launching airstrikes against the forces of the Libyan dictator Colonel Gadaffi amid fears of a massacre of rebels who had risen up against his rule.
However, in 2013 he was forced to abandon plans for strikes against Syria’s President Bashar Assad, in response to the use of chemical weapons against rebels there, after losing the vote on a Commons motion calling for military action.
After the SNP secured an outright majority in the Scottish Parliament in the election of 2011, Mr Cameron agreed to allow first minister Alex Salmond to hold a referendum on Scottish independence.
Although the result of the vote in September 2014 was a defeat for independence, it nevertheless ushered in almost a decade of SNP dominance of Scottish politics.
– 2015 to 2017: The Brexit referendum
The 2015 general election saw the Tories unexpectedly returned with an outright majority while the Lib Dems paid the price for their support for the government’s austerity policies with a near-wipeout to bring the coalition to an end.
Back in No 10, Mr Cameron set about wooing communist China, the world’s rising economic superpower, rolling out the red carpet for a state visit for President Xi Jinping – and even inviting him for a pint at his local.
However, the new parliament was dominated by Mr Cameron’s promise to hold an in-out referendum on Britain’s membership of the European Union in an attempt finally to put and end to years of Tory wrangling.
His hopes of securing a vote to Remain suffered a major setback when outgoing London mayor Boris Johnson – then one of the most popular and most recognisable politicians in the country – agreed to front the Leave campaign.
Mr Cameron attempted to renegotiate the terms of Britain’s membership in an effort to boost support for staying in but was unable to secure the level of concessions he was hoping for – particularly on the free movement of labour.
When it came to the vote on June 23 2016, the result was a victory for Leave – by 52% to 48%. Within hours of the declaration, Mr Cameron emerged on the steps of No 10 to announce he was standing down.
Mr Johnson was widely expected to succeed him but his leadership bid was dramatically scuppered when his fellow Leave campaigner Michael Gove turned against him, declaring him unfit for office.
It was home secretary Theresa May, a Remain supporter albeit a fairly lukewarm one, who emerged from the wreckage as the last candidate standing, entering No 10 as prime minister on July 13.
In an attempt to shore up her position with Tory Leavers, she appointed Mr Johnson as foreign secretary while David Davis was made Brexit secretary overseeing negotiations with the EU on the terms of Britain’s departure.
Following the election of Donald Trump as US president, she became the first foreign leader to fly to Washington to meet him, marking the start of what was to be an increasingly fractious relationship.
– 2017 to 2019: Tories at war
Buoyed by an early bounce in opinion polls, in April 2017 Mrs May decided to call a snap general election in the hope of strengthening her hand in the forthcoming Brexit negotiations – both with Brussels and with her own MPs.
She proved, however, to be a poor campaigner, while Labour leader Jeremy Corbyn was an unexpected hit with younger voters.
The result was the loss of the Tories’ Commons majority – with Mrs May forced to turn to Northern Ireland’s Democratic Unionists (DUP) to prop up her suddenly shaky-looking administration at Westminster.
What followed was an unprecedented period of parliamentary turmoil, with the Tories hopelessly divided between former Remainers who were pressing for a “soft” Brexit, and hardline Leavers demanding a clean break with the EU.
After a pre-dawn dash to Brussels, the prime minister finalised an agreement with European Commission president Jean-Claude Juncker but the deal – including the infamous Northern Ireland “backstop” – was denounced by hardliners as “Brexit in name only”.
Meanwhile, troubles were piling up elsewhere with the disclosure that her “hostile environment” policy had led to scores of legal immigrants from the so-called Windrush generation being wrongly stripped of their rights while she was criticised for her tone-deaf response to the Grenfell Tower fire tragedy.
A cabinet meeting in Chequers intended to unite ministers behind her Brexit strategy, aimed at maximising UK access to EU markets, only brought further chaos when first Mr Davis and then Mr Johnson quit in protest.
With the mood in the party becoming increasingly rancorous, Mrs May survived a no confidence motion by rebellious Tory MPs but when she finally put her deal to a Commons vote in January 2019 she lost by 230 votes – the biggest government defeat in modern political history.
In the past it would have led to the fall of the government but with Tory MPs in no mood to vote for an election they knew they would lose, the Fixed Term Parliaments Act (FTPA) – passed under the coalition – meant she was simply left to limp on.
Two further votes and two further government defeats followed – albeit by smaller margins – but when an unlikely attempt to broker a deal with Labour collapsed she finally accepted she had run out of road and in May she emerged from No 10 to tearfully announce her resignation.
In the ensuing leadership contest, this time Mr Johnson emerged triumphant, easily beating Jeremy Hunt in the final run-off ballot of party members.
He straight away announced his intention to renegotiate the terms of Mrs May’s Brexit deal, eventually securing agreement with Irish premier Leo Varadkar to replace the backstop with a customs border between Northern Ireland and the rest of the UK – a measure that was to prove almost as contentious.
The Commons remained deadlocked with a block of pro-Remain Tory MPs firmly opposed to his plans. In an attempt to shut down debate Mr Johnson ordered an extended prorogation of parliament only for the Supreme Court to rule he had acted unlawfully.
The position at Westminster was however becoming increasing untenable as Mr Johnson withdrew the Tory whip from more than 20 rebels – including ex-chancellors Kenneth Clarke and Philip Hammond – for voting with the opposition.
Finally, in October 2019, after three unsuccessful attempts to secure the two thirds majority needed to call a general election under the FTPA, the Commons agreed to an emergency Bill dissolving parliament, with polling day set for December 12.
– 2019 to 2021 Covid, scandal and chaos
Mr Johnson campaigned on the promise to “get Brexit done” combined with a commitment to “level up” those areas of the country which had been increasingly left behind in the preceding decade.
The result was a landslide, with an 80-seat majority for the Conservatives – the party’s biggest win since the days of Margaret Thatcher – as a series of previously safe Labour “red wall” seats in the North and Midlands fell to the Tories.
MPs returned to Westminster to rush through ratification of the Brexit withdrawal agreement before the Christmas break and at 11pm GMT on January 31 47 years of British membership of Europe came to an end.
But a new crisis was already looming with the emergence in the Chinese city of Wuhan of a terrifying new coronavirus infecting humans, designated Covid-19.
As the virus began its inexorable spread around the globe, Mr Johnson appeared slow to appreciate the threat, leaving health secretary Matt Hancock to chair a series of meetings of the Cobra civil contingencies committee.
On March 23, nearly two months after the first confirmed case in the UK, the prime minister ordered an unprecedented national lockdown, with people ordered to stay at home, bringing economic activity to a halt.
At the same time, chancellor Rishi Sunak unveiled an equally unprecedented furlough scheme for the state to pay the wages of millions of workers who would otherwise have been laid off.
The national mood of uncertainty was only heightened with the news that Mr Johnson had been admitted to intensive care after falling victim to the virus: for three days it appeared touch and go whether he would survive.
The government faced criticism for its at-times chaotic response to the crisis, with lockdowns lifted and then reimposed, a shambles over the acquisition of vital protective equipment for hospital staff and a confused test and trace programme.
However there were also plaudits for the speed with which it was able to role out a mass vaccination programme, once first inoculations became available.
By the time the outbreak subsided, at least 235,000 people in the UK had Covid recorded on their death certificate.
As the country gradually emerged from the pandemic, Mr Johnson found himself increasingly embroiled in scandal, including claims he had secretly arranged for Tory donors to pay for a lavish refurbishment of his Downing Street flat.
Health secretary Matt Hancock had to resign after CCTV footage was leaked to the press showing him cavorting in his office with his mistress in violation of social distancing guidelines.
Most damaging however was the emergence of reports of No 10 staff holding drinks parties – some attended by Mr Johnson himself – in apparent breach of the government’s own lockdown regulations.
The country was appalled at the increasingly lurid revelations – including a night of drunken revelry on the eve of the funeral of the Duke of Edinburgh – while the prime minister was accused of lying to parliament as he insisted no rules had been broken.
Following an investigation by the Met Police, he was subsequently issued with a fixed penalty notice, along with Mr Sunak and dozens of No 10 staff, becoming the first British prime minister to be sanctioned for breaking the law while in office.
President Vladimir Putin’s invasion of Ukraine in February 2022 meant the focus temporarily shifted away from domestic politics, with Mr Johnson at the forefront of rallying international support for the beleaguered government of Volodymyr Zelensky.
However when it emerged he had been warned about the conduct of deputy chief whip Chris Pincher – who was accused of indecently assaulting two men in the Carlton Club – before he appointed him to the post, it was a scandal too far.
Health secretary Sajid Javid and Mr Sunak resigned in quick succession, triggering an avalanche of further resignations – many by ministers who felt they had been sent out to lie on Mr Johnson’s behalf.
The prime minister tried to hang on but it soon became clear the position was untenable and on July 7 he appeared on the steps of No 10 to announce he was quitting.
In the ensuing leadership contest it was foreign secretary Liz Truss who came out on top – beating Mr Sunak in the final ballot of activists, many of whom blamed him for bringing down Mr Johnson, who remained hugely popular among ordinary members.
Within two days of the new prime minister taking office, politics as normal was suspended as the country entered 10 days of national mourning following the death of Queen Elizabeth II.
When government business resumed Ms Truss was impatient to get on with delivering her keynote campaign promise of tax cuts to kick-start economic growth, even though she had not fully worked out how they would be paid for.
Chancellor Kwasi Kwarteng’s ensuing mini-budget – delivered without the Office for Budget Responsibility having had the chance to run the rule over his figures – was a disaster.
The pound plummeted as the markets took fright at the £45 billion package of unfunded tax cuts while the Bank of England had to step in to prevent pension funds collapsing.
Mr Kwarteng was summoned back early from a meeting of the IMF in Washington to be sacked by Ms Truss but it was too late to save her.
On October 20 she bowed to the inevitable and announced she as resigning, the fourth Conservative prime minister to do so in the space of a little over six years.
She had lasted just 49 days in office, making her the shortest-serving premier in British history.
There was no mood in the party for another extended leadership contest and after Mr Johnson decided against attempting an unlikely political comeback, Mr Sunak was elected unopposed.
He entered No 10 promising stability after the turmoil of the previous years, however that was not enough to turn around the Tories’ fortunes in the opinion polls.
Voters appeared in no mood to forgive after seeing living standards painfully squeezed, in part the legacy of Covid and the war in Ukraine, while the NHS struggled to recover from the pandemic.
Migration was also rising up the agenda once again, with many Tory MPs demanding tougher action to stop the small-boat crossings in the Channel as the plan to deport illegal entrants to Rwanda remained stuck in the courts.
In a final roll of the dice, a rain-soaked Prime Minister attempted to regain the initiative with the announcement that he was going for a July election, rather than wait to the autumn as had been generally expected.
After 14 years continuously in office, it was the beginning of the end for the Conservatives.
