Mr Cummings was one of Mr Johnson’s first appointments when he succeeded Theresa May as Conservative Party leader and PM in the summer 2019. His hiring was a signal to the hard-line Brexiteers who had ushered Mr Johnson to power that he was serious about delivering the withdrawal agreement from the European Union that his successor had failed to secure over months of tortuous negotiations.
A political strategist, Mr Cummings was an influential special adviser to Michael Gove between 2007 and 2014 before he became director of the Vote Leave campaign in 2015 and masterminded its victory in the Brexit referendum of 2016. He coined its “take back control” slogan and was seen as a divisive and outspoken figure who made enemies easily.
Portrayed as a visionary anti-establishment disrupter by Benedict Cumberbatch in the Channel 4 film Brexit: The Uncivil War, Mr Cummings was once described by David Cameron as a “career psychopath” and caused offence in Conservative circles by dishing out withering insults. He memorably labelled former Brexit secretary David Davis “thick as mince” and “lazy as a toad”, said the European Research Group were “useful idiots for Remain” and described the civil service as a “blob” of incompetence and bureaucracy.
It was six months into Mr Cummings’ tenure in Downing Street that the coronavirus pandemic arrived in Britain, a global emergency that forced the country into lockdown and which saw him cause public outrage by appearing to breach the very rules he had helped to draft. That scandal would secure his infamy and ultimately bring an acrimonious end to his relationship with Mr Johnson.
Here is a brief overview of his tumultuous time in Westminster’s corridors of power.
Dominic Cummings entered No 10 Downing Street as senior adviser to Boris Johnson on 24 July.
He sparks a row at the Treasury by dismissing special adviser Sonia Khan and having her frogmarched out of the building by armed security without the knowledge of then-chancellor of the exchequer Sajid Javid. Her sacking was reportedly over his anger that she had remained in contact with her former boss Philip Hammond.
Mr Cummings faces questions from Labour’s shadow foreign secretary Emily Thornberry over his alleged ties to Russia in response to a whistleblower coming forward to raise “serious concerns” about the time he spent living and working there between 1994 and 1997, shortly after graduating with a degree in ancient and modern history from Exeter College, Oxford.
Ms Thornberry seeks reassurances regarding the security clearances he has been granted, in view of his potential access to highly classified material.
Mr Johnson’s Conservatives romp to a landslide general election win over Jeremy Corbyn’s Labour on 12 December, with the PM singling out Mr Cummings for particular praise in his victory speech.
Mr Cummings raises eyebrows by posting a job advert calling for “super-talented weirdos”, “wild cards” and “unusual mathematicians” to apply to work with him at No 10.
Mr Javid resigns as chancellor on 13 February as Mr Johnson reshuffles his cabinet. It later emerges that he was told by the PM that he could keep his job so long as he agreed to allow Mr Cummings to pick and choose his advisers.
Speaking to the Press Association, Mr Javid says: “No self-respecting minister would accept those terms.”
As the first cases of Covid-19 are reported in the UK, Mr Johnson reluctantly places the public under strict lockdown measures on 23 March to stop the spread of the deadly respiratory disease, ordering people to stay indoors and minimise contact with others outside of their immediate family unit.
Mr Johnson and health secretary Matt Hancock both test positive for Covid on 27 March, as does Mr Cummings on 30 March, prompting him to self-isolate.
It emerges on 5 April that Mr Cummings is the person Durham police had spoken to a week earlier about breaching lockdown rules by driving from London to the northeastern city after he was spotted in his parents’ garden when he ought to have been under quarantine in the capital.
On 12 April, a member of the public reports seeing Mr Cummings at Barnard Castle, around 30 miles from Durham. The adviser returns to work at Downing Street on 14 April, having recovered from the virus.
After Mr Johnson’s government loosens lockdown restrictions for the first time, news of Mr Cummings’ alleged rule breaches is published on 22 May by The Mirror and The Guardian.
As a media storm brews, he receives the support of Downing Street and Mr Johnson and insists that he acted “reasonably and legally”.
Facing calls to resign from Liberal Democrats’ leader Sir Ed Davey and Ian Blackford of the Scottish National Party, Mr Cummings delivers a press conference from the Downing Street Rose Garden on 25 May in which he attempts to clarify his movements and justify his conduct. He claims that he had travelled to Barnard Castle to test his eyesight after recovering from Covid, a line that invites bitter derision.
On the same day, YouGov publishes a poll that finds that 71 per cent of the British public believes he broke the rules and that 59 per cent felt he should resign.
On 28 May, Durham Police say they concluded that no breach of the rules occurred when Mr Cummings drove from London to Durham and that they planned to take no action over the Barnard Castle incident.
The respected medical journal The Lancet publishes a report into the “Cummings effect”, examining the affair’s role in undermining the British public’s faith in the government’s guidelines for tackling the coronavirus.
Following the departure of Lee Cain, Downing Street’s director of communications, on 13 November, now also appearing before the Covid inquiry, Mr Cummings’ joins him in heading for the exit a day later.
Rumours begin to circulate of a battle for influence within the building between the adviser and Mr Johnson’s wife, Carrie Johnson.
In the months that follow, Mr Cummings becomes a persistent and vicious critic of the government he once represented via his personal blog while Mr Johnson and his administration become embroiled in the “Partygate” scandal, alleging further lockdown breaches within Westminster.
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