Sir Terry Wogan will not host BBC1â€™s Children in Need appeal for the first time in its 35-year history due to poor health.
The 77-year-old presenter said he would miss presenting the â€œwonderful, inspiring eveningâ€ on Friday night, but would be watching, cheering and donating.
â€œThe British public, as always, will dig deep in their pockets and purses to help the countryâ€™s disadvantaged children, knowing that every penny will go to those who need it most,â€ he said.
A BBC spokesman said that Wogan was having a procedure on his back and, under doctorâ€™s orders, cannot host a six-and-a-half hour show, adding: â€œWe are so sorry that Terry wonâ€™t be with us tomorrow night as we know how passionate he is about Children in Need. We wish him a very speedy recovery.â€
A replacement host would be announced in due course, the BBC said.
Strictly Come Dancingâ€™s Tess Daly, along with Radio 1 breakfast host Nick Grimshaw, Fearne Cotton and Rochelle Humes, are due to co-present the live broadcast.
â€œThe show will go on, bigger and better than ever, in the hands of my friends, Grimmy, Fearne, Rochelle and Tess,â€ said Wogan.
The veteran presenter recently admitted that he â€œprobably drinks too muchâ€, but walked for 30 minutes a day and ate a lot of fruit and vegetables.
As the presenter of the Eurovision Song Contest on BBC1 from 1971 to 2008, Wogan was renowned for getting tipsier as the marathon broadcast wore on.
Wogan told the Daily Record he had no plans to retire: â€œTheyâ€™ll have to carry me off stage. I do seven hours on my feet of live television for Children in Need every year, so the day that I canâ€™t stand up is when I will stop doing it.
â€œIâ€™d love to keep going for another 10 years â€“ Iâ€™ll cling to the wreckage for as long as I can.â€
He had faced criticism in previous years after it emerged he had been paid Â£1,300 an hour for hosting the annual charity appeal on BBC1, although he insisted he did not know about the fee and had waived it.
One Direction and Dame Helen Mirren are among the stars set to appear on Children in Need this year, while Jess Glynne will perform the official single, Take Me Home.
Actors David Tennant and Martin Freeman and singer Ellie Goulding are also expected to present some of the projects funded by the appeal.
Goulding will also perform her new single On My Mind and there will be an exclusive Star Wars sketch with C3PO and R2-D2 alongside Star Wars actor Warwick Davis.
There will also be a Call the Midwife Strictly special and performances from acts including Years & Years and Selena Gomez.
Children in Need starts at 7.30pm on Friday on BBC1.