Organisers of the Lytham Festival announced at the last minute that The Human League would not be able to perform in the headliner slot of the festival's 80s v 90s night due to illness.
A spokesman for the Lancashire-based festival said: "Unfortunately, a member of The Human League was taken seriously ill while on site at Lytham Festival resulting in the band being unable to perform.
"They are now under the care of a doctor and we wish them a speedy recovery.
“We apologise wholeheartedly to everyone but this is something completely out of our control."
The chart-topping band released a statement on their Facebook page last night.
It read: "Just a very brief note to say we are extremely sorry that we were unable to perform for you all at the Lytham Festival tonight, it really was unavoidable we're afraid.
"We will post a more fulsome explanation tomorrow but in the meantime we would just like to thank you all for your understanding and the promoters Cuffe and Taylor for their kind assistance and professionalism.
"Again our sincere apologies, we will make it up to you we promise."
The Human League, best known for 80s chart smashes such as Don't You Want Me and Love Action, were due to perform on the third night of the festival along with 80s pop star, Midge Ure and 90s acts including A1 and Dodgy.
The line-up of the popular Sheffield band features lead vocalist Phil Oakley, 61, Joanne Catherall, 54 and Susan Sulley, 54. Read more: http://www.dailymail.co.uk/tvshowbiz/article-4763250/Human-League-band-member-struck-mystery-illness.html#ixzz4osX67azJ Follow us: @MailOnline on Twitter | DailyMail on Facebook