The 47-year-old singer, who has already undergone two operations on his spine, has been left ''distraught'' that he has been forced to cancel the shows - in support of their comeback album 'Automation' - because of the ongoing health problem.
However, the 'Virtual Insanity' hitmaker has vowed to return ''stronger'' and better than ever to make it up to his fans.
He wrote on Facebook: ''Hi J here,
''It is with great regret that again I have to disappoint people due to the ongoing problem with my back. I have never felt so frustrated with a situation as I feel now, and I am desperate to get back to form. After two operations I am only marginally more active, and I know I could never give the 125% energy I need to give to you good people a super show. I am a proud man, and it breaks my heart to have to keep moving these performances and asking for people's patience. I am distraught at this and am feeling very low ... (sic)''
Jay also said mourning the loss of his friends, including death of the funk and acid jazz's group's founding member Toby Smith in April, has taken its toll on him.
The 'Cosmic Girl' star has thanked fans for being patient with regards to the shows being pushed back to December.
He continued: ''2017 is turning out to be a tough year, with the loss of several close friends in quick succession and the inability to perform properly in the way I've been doing, and the only way I know how to, since I did my first gig at 17 years old.
''I want to thank all of you for the messages of support you have sent me. I can't quite believe how kind you all are. A thousand thanks.
''I want to apologise to all of you who have no doubt made travel plans and taken time out to see us in Paris, Athens and London O2, but I give you my word - I promise you I will come back and give you the shows you deserve. Faster, harder and stronger.
''Thank you all so much once again for your unerring love and patience, your posts have really picked me up.
''From a very wounded Buffalo.
''Lots of love,
The London shows have been reschedule for December 3 and December 6.
A representative for the band said: ''Please note that tickets for the postponed O2 show on Friday 23rd June will only be valid for the rescheduled show on Sunday 3rd December. Tickets for the O2 show on Saturday 24th June will only be valid for Wednesday 6th December.''