OpenAI staff threaten to quit unless Sam Altman returns; Abu Dhabi fund lined up to take control of Telegraph – as it happened

Around 500 employees of OpenAI have signed a letter saying they may quit and join Sam Altman at Microsoft, unless he is reappointed and the board resigns

• Full story: Microsoft hires former OpenAI CEO Sam Altman
• Analysis: Sam Altman's OpenAI exit leads to rollercoaster for sector
• Full story: Sunak says he will cut taxes over time' as he reveals new economic priorities

Spotify CEO Daniel Ek has reached for a popular meme to sum up the AI turmoil:

Microsoft's shares are up over 2% in premarket trading, after announcing the hiring of Sam Altman and Greg Brockman to lead a new AI research team.