Drawing on more than 100 interviews with senior intelligence officials and other insiders in multiple countries, this exclusive account details how the US and Britain uncovered Vladimir Putin’s plans to invade, and why most of Europe – including the Ukrainian president, Volodymyr Zelenskyy – dismissed them. As the fourth anniversary of the invasion approaches and the world enters a new period of geopolitical uncertainty, Europe’s politicians and spy services continue to draw lessons from the failures of 2022

After speaking to locals, I still can’t predict the result, but a big, combined effort will be needed. Without a united front the left may splinter and lose

You don’t have to be in Gorton and Denton for long to know that next week’s byelection really matters. If Labour wins in what has been an over-50% solid red-voting area since the second world war, that will calm nerves on its febrile back (and front) benches. If Labour loses, heavy blame will fall on Keir Starmer for fixing the party’s ruling NEC to bar Andy Burnham’s selection, ensuring he couldn’t challenge for the leadership without a Westminster seat.

Few doubt the popular Greater Manchester mayor would have won next week in Gorton and Denton on his home patch. Blocking him is widely seen as grubby Westminster politicking that has weakened, not strengthened, Starmer’s grip on the leadership. For many erstwhile supporters that jiggery-pokery was a turning point, as Starmer seemed willing to risk Reform UK scoring another win in order to stop Burnham, though “stop Farage” has to be Labour’s overwhelming priority.

Polly Toynbee is a Guardian columnist

Mopping floors, dressing up as kids’ entertainers and fishing unmentionable things from swimming pools: the Dyers’s new TV show sees them investing in a caravan park. Can they revive the UK’s love of them?

“You wouldn’t see Olivia Colman doing this bollocks would you?” jokes Danny Dyer as he clears up a dustbin at Priory Hill & Nutts Farm Holiday Park in Kent.

But over the past year – around filming the return of the hit Disney+ series Rivals – the actor, and his daughter Dani, have been spending weekends on the Isle of Sheppey, filming The Dyers’ Caravan Park (Sky One) in an attempt to boost the fortunes of Priory Hill and make caravanning cool.

Kraków’s ban on burning solid fuels plus subsidies for cleaner heating has led to clearer air and better health

As a child, Marcel Mazur had to hold his breath in parts of Kraków thick with “so much smoke you could see and smell it”. Now, as an allergy specialist at Jagiellonian University Medical College who treats patients struggling to breathe, he knows all too well the damage those toxic gases do inside the human body.

“It’s not that we have this feeling that nothing can be done. But it’s difficult,” Mazur said.

It caused a scandal in imperial Russia, then became a staple of popular art in the USSR. But when I spied a copy of Ivan Kramsky’s portrait in the film Sentimental Value, it opened a door to an untold case of life imitating art

Sentimental Value is one of those films you have to watch very closely. In the Norwegian director Joachim Trier’s latest work, which swept the board at the European film awards and is nominated for eight Baftas and nine Oscars, stories are hidden in closeups, half-tones and peripheral objects. Some of these stories are so well hidden, in fact, that they aren’t even apparent to the people who made the film.

In one scene, roughly an hour in, the camera glides down a corridor, and suddenly there she is: a woman’s portrait on the wall. Anyone who grew up in the Soviet Union and later Russia between the 1950s and 2000s, like me, would recognise her instantly. She has been endlessly reproduced: as prints, embroideries, portrait medallions, even on boxes of chocolates. In Britain, people may have encountered her on the covers of various editions of Anna Karenina.

Information content manager Rosie Weatherley says harmful inaccuracies are presented as uncontroversial facts

• Mind launches inquiry into AI and mental health after Guardian investigation

A year-long commission has been launched by Mind to examine AI and mental health after a Guardian investigation exposed how Google’s AI Overviews, which are shown to 2 billion people each month, gave people “very dangerous” mental health advice.

Here, Rosie Weatherley, information content manager at the largest mental health charity in England and Wales, describes the risks posed to people by the AI-generated summaries, which appear above search results on the world’s most visited website.

The arrest of the 66-year old former prince has sent shockwaves through the UK and abroad, with reaction rolling in from the US to Australia

• King: ‘The law must take its course’

• Friday’s newspaper front pages

The family of Ghislaine Maxwell, who is serving 20 years in prison for helping Jeffrey Epstein sexually abuse underage girls, responded last night to Andrew Mountbatten-Windsor’s arrest.

“Astonished to see Andrew Mountbatten-Windsor arrested today over alleged misconduct in public office linked to material from the so‑called Epstein ‘Files’,” they posted on an X account run by Maxwell’s siblings.

Exclusive: Josh Simons pressed intelligence officials to investigate reporters, in emails described as ‘McCarthyite smear’

A Labour minister who claimed to be “surprised” and “furious” at a PR agency’s work to investigate journalists on his behalf had been personally involved in naming them to British intelligence officials and falsely linking them to pro-Russian propaganda, the Guardian can reveal.

Josh Simons, who was running the thinktank Labour Together at the time, was also involved in telling security officials that another journalist was “living with” the daughter of a former adviser to Jeremy Corbyn. Officials were told by Simons’ team that the former adviser was “suspected of links to Russian intelligence”.

Largest January total since records began in 1993 is sharp reversal from December’s £11.6bn deficit

• Business live – latest updates

The UK government has posted the biggest ever budget surplus, official figures show, after a large increase in self-assessment and capital gains tax receipts.

In a boost for the chancellor, Rachel Reeves, in the run-up to her spring statement next month, public sector finances recorded a surplus of £30.4bn at the start of the year, according to the Office for National Statistics. This was double the surplus recorded in January 2025.

US president links deal with military strikes against Iran in connection with Tehran’s nuclear ambitions

Donald Trump changed his mind on supporting the Chagos Islands deal because the UK will not permit its airbases to be used for a pre-emptive US strike on Iran, the Guardian has been told.

In his latest change of heart on the deal, the US president said on social media that Keir Starmer was “making a big mistake” by handing sovereignty of the islands to Mauritius in exchange for continued use by the UK and US of their airbase on one of the islands, Diego Garcia.