Lewis Hamilton is poised for a shock move from Mercedes to Ferrari for the 2025 season, BBC Sport understands.
A number of sources say a deal for Hamilton to join Charles Leclerc at Ferrari from 2025 has been agreed but both teams have refused to comment.
The move, one of the most seismic events in Formula 1 for years, could be announced as early as Thursday.
The 39-year-old signed a new two-year deal with Mercedes last summer but he is set to leave just one year into it.
The possibility of Hamilton moving to Ferrari in 2025 was reported in the Italian and Spanish media on Thursday.
BBC Sport has since verified the information and a number of senior sources say the move will happen and will be confirmed in the near future.
There have been intermittent rumours of Hamilton moving to Ferrari for years. Until now, these have turned out to have little substance, but a number of sources say this is different.
Sources have told BBC Sport that all Mercedes team members have been called to a team briefing with boss Toto Wolff and technical director James Allison at 14:00 GMT on Thursday. This is likely to be to announce Hamilton is leaving.
The Hamilton deal has happened quickly. Ferrari were in negotiations over a contract extension with Carlos Sainz, whose deal runs out at the end of this season.
But Ferrari president John Elkann then discovered that Hamilton was a possibility and moved to secure his signature. The two are friends and have met each other socially on a number of occasions in recent years.
Hamilton won the most recent of his seven world titles in 2020 and signed his latest two-year Mercedes deal in August, which would extend his period with the team to 13 years.
Ferrari admitted to holding talks with then-reigning world champion Hamilton in 2019 about joining them in the future.
Red Bull have dominated the sport over the past two seasons since the controversial 2021 Abu Dhabi Grand Prix, when Hamilton lost out to Max Verstappen after former FIA race director Michael Masi ignored the rules in operating a late-race safety car period.
Since then, he has been driven by the desire to avenge what he believes to be an injustice and win his eighth title.
At the end of last season, Hamilton was sounding equivocal about his belief in Mercedes’ ability to recover from two difficult seasons and challenge Red Bull.
In an interview with BBC Sport and other selected outlets at the final race of the season in Abu Dhabi, he said: “I do believe we have a North Star now. Which I don’t think we’ve had for two years. But still getting there is not a straight line.
“I think we understand the car so much better. They have developed great tools in the background. So naturally, I’m hopeful, but I’m not going to hold my breath.”
Ferrari have also had a difficult few seasons, and the two teams were locked in a battle for second in the constructors’ championship last year, which Mercedes narrowly won despite the Ferrari being the faster car by the end of the season.
Hamilton’s move will send shockwaves through F1 – similar to those when he chose to leave McLaren for Mercedes for the 2013 season.
At the time, many questioned Hamilton’s decision, but it turned out to be remarkably prescient – he and the team dominated F1 from the 2014 season, making the Briton the most successful driver in F1 history.
The lure of Ferrari, the sport’s most historic and evocative team, is strong for many drivers. Until now, Hamilton seemed to be immune to it – he has said on several occasions that he wanted to spend the rest of his life with Mercedes, and the pair have a number of projects together, especially on diversity and racial equality.
But it seems the chance to spend the final years of his career driving for Ferrari may be too good to turn down – it is something Hamilton’s boyhood idol Ayrton Senna was also planning to do before he was killed in a crash while driving for Williams in the 1994 San Marino Grand Prix.
Hamilton’s move will explode the F1 driver market.
Mercedes would be looking for a replacement for Hamilton at the end of the season, Ferrari’s Sainz would be looking for a new job.
And other than Fernando Alonso, whose Aston Martin contract expires this season, none of the recognised top drivers would be available to join Mercedes alongside George Russell.
Max Verstappen is contracted to Red Bull until 2027, Leclerc is committed to Ferrari and Lando Norris has also just signed a new deal at McLaren.
Analysis – Has Hamilton got it right again?
Hamilton’s move to Ferrari is one of the biggest – and most surprising – stories in F1 for years.
Hamilton has always insisted he wanted to spend the rest of his career and beyond with Mercedes – likening his situation to that of the late Stirling Moss, who was a Mercedes ambassador for his whole life.
But things have changed and Hamilton has decided he cannot turn down the lure of Ferrari, whose history, legend and mystique is always a strong pull for any F1 driver.
Hamilton remains the biggest star in F1, as well as its most successful ever driver, and his decision to leave Mercedes is a huge blow to a team with whom he signed a new two-year contract only a few months ago.
His decision is as big a vote of confidence in Ferrari’s team principal Frederic Vasseur – with whom Hamilton has remained close since working with him in the junior categories – as it is the opposite for Mercedes.
Both have struggled against Red Bull in the last two years since new rules were introduced but Hamilton must see something in Ferrari’s progress over the latter part of last season.
It’s impossible to consider the reasons behind this move, or its consequences, without the context.
Hamilton was badly hurt by the events of the 2021 Abu Dhabi Grand Prix. He believes he was robbed of an eighth world title by race director Masi’s failure to follow the rules correctly with the operation of a safety car late in that race.
Since then, he has been driven by a desire to avenge that injustice – even if he has not quite put it that way in public.
With Mercedes, back in 2012, his judgement was remarkable – he proved wrong everyone who doubted his decision to move from McLaren, and embarked on the most successful period an F1 team and driver have ever had together.
Has he got it right again, or has he just made a decision he will ultimately regret?.