Michael Beloff QC has announced he is leaving 4-5 Gray's Inn Square but he is joining Blackstone Chambers and not Matrix Chambers as expected.
The surprise move major setback for the set which was launched last year with a complement of 4-5 Gray's Inn Square tenants, including Cherie Booth QC.
Beloff announced last spring after much speculation that his 'present intention' was to join the then fledgling set in 2001.
The time delay was in order to help 4-5 Gray's Inn Square's proposed merger with Monckton Chambers.
But Bentham Chambers as it was known, foundered last summer and since then Beloff's ultimate intentions were not known.
On Tuesday Beloff announced that Blackstone Chambers was to benefit from his services and he viewed this as a homecoming, for he had practised at the set then known as 2 Hare Court from 1968 up to 1985.
He said: "After careful consideration of a range of attractive offers, I have decided to rejoin the outstanding set which gave me my first chance at the Bar, and where I can practise again in the company of many former colleagues."
Charles Flint QC, co-head of Blackstone Chambers, said: "Michael's reputation is formidable and his practice will complement our strengths across the spectrum of our practice
Senior clerk Michael Kaplan wished him well and added: "It is something we were expecting so it has not come as a complete surprise as he mentioned he was going a year ago."
"We always hoped we could persuade him to stay, but we know this is not a decision he took lightly."
Nick Martin chief executive of Matrix Chambers noted: "We have been aware for some time that there was uncertainty about where Michael wished to continue his professional practice. We wish him well at Blackstone."