Boris Johnson’s former chief adviser has raged against both the Conservatives and Labour, claiming neither are focused on "being a serious government".
In the wake of Labour’s Hartlepool by-election defeat, Dominic Cummings branded the party’s leader Sir Keir Starmer as a "beta-lawyer-gamma-politician" who "obsesses on media reality not actual reality".
He also claimed he had no knowledge of who Labour’s shadow chancellor was until he conducted an internet search the day before Thursday’s vote – before going on to present a scenario in which he believes the party would "win the next general election easy".
But, in a series of Twitter posts, Mr Cummings’s ire was not solely reserved for Labour and Sir Keir, as he also took another swipe at the prime minister.
Mr Cummings has been engaged in a recent briefing war with Number 10 following his departure as Mr Johnson’s top aide in November last year.
In a by-election result announced early on Friday morning, Labour lost the Hartlepool constituency for the first time since the seat’s creation more than 47 years ago.
The result delivers another brick in Labour’s "red wall" to the prime minister, following the inroads Mr Johnson made into Labour’s traditional heartlands at the 2019 general election.
And Mr Cummings seized on the result as vindication of his strategy as head of Vote Leave during the 2016 EU referendum and for the Tories campaign in 2019.
He told people to "ignore" the "babble" of "pundits who ‘explained’ why Vote Leave’s plan to realign politics was mad/stupid/impossible" but "now give post hoc ‘explanations’ for why it’s all so logical/inevitable".
Mr Cummings added Vote Leave’s success was based on their belief that talk of a political "centre ground" was "false.
"SW1 didn’t learn after 2016 & provided a chance for us to win again in 19, ignoring pundit howling," he tweeted.
As well as linking to a previous blogpost of his about swing voters’ concerns with immigration, Mr Cummings accused Sir Keir of having spent a year as Labour leader "without a message to the country" and urged him to make a "sustained effort on violent crime".
But he suggested Sir Keir would continue to focus on "media priorities" ahead of "public priorities" and offered one example of "how bad" he believed the Labour leader had performed.
He said "until I googled it yesterday", he didn’t know who Labour’s shadow chancellor was – and that when he looked at a photo of Anneliese Dodds, he still did not recognise her.
"She never touched my consciousness in a year," Mr Cummings said, although he added the "caveat" that he "ignored politics/communication" as much as he could in 2020.
Mr Cummings advised Sir Keir to hire David Shor, an American data scientist who worked on former US president Barack Obama’s re-election campaign in 2012, and to tell Labour’s shadow cabinet "to do as he says".
He claimed Mr Shor "understands politics better" than any Labour MP or Sir Keir’s office.
Mr Cummings also used his string of tweets to lash out at Mr Johnson’s Downing Street operation.
"We have a No10 & Opposition who see their job as Media Entertainment Service," he posted, adding: "Neither will try to be… a government."
Mr Cummings predicted UK politics "will for a while" resemble the early 2010s when ex-prime minister David Cameron and his chancellor George Osborne faced Labour’s Ed Miliband.
"Two groups focused on the media but not as good at it as (Tony) Blair, neither focused on country or *being a serious gvt*," he said.
He added that if Labour had a leader "80% as good" at communications as Mr Blair and "focused on ActualReality, they’d win next [general election] easy".
Mr Cummings also offered a warning that if decisions over COVID vaccines had been "conventional" then "today would have been terrible" for the Conservatives.
However, Conservative MP Steve Baker – a prominent Brexiteer and a critic of Mr Cummings – said he wondered "why people pretend to be infallible" in response to Mr Cummings’s long string of tweets.
He claimed Mr Cummings "noisily supported" calls for MPs to back Theresa May’s Brexit deal at the third time of asking.
Mr Baker said this would have "destroyed" the Conservative Party and made Jeremy Corbyn prime minister.
"Thankfully, we successfully opposed it and set a better course," Mr Baker said of his group of Brexit "spartans" who continually opposed Mrs May’s deal.
Mr Cummings’ latest attack on Number 10 comes after his publication of a 1,000-word blogpost last month in which he made a series of allegations about Mr Johnson.
It included claims about the funding of the prime minister’s refurbishment of his Downing Street flat.