Leon Bernicoff, one of the stars of the Channel 4 series Googlebox, has died, aged 82, after a short illness.
The retired teacher and his wife June were one of the first couples to join the show's cast when it launched in 2013.
In a statement on behalf of the Bernicoff family, Channel 4 and production company Studio Lambert said: "It is with a heavy heart that we announce the sad news that after a short illness Gogglebox's Leon Bernicoff passed away in hospital earlier today.
"Leon and his wife June were the first members of the public to be cast for Gogglebox back in early 2013, and they soon grew to become much-loved voices during the course of the show's 10 series to date.
"Leon's unique personality and sharp wit endeared him to fans of the show, as he contributed fully to Gogglebox's reputation as a programme full of warm humour and unvarnished opinion.
"To those of us that knew him personally, Leon was a man of unwavering principles who exerted a distinct paternal presence both on and off screen. He will be dearly missed by the entire Gogglebox family; cast and crew.
"Our thoughts are with June, his two daughters, sons-in-law and beloved grandchildren - all of whom have asked for their privacy to be respected at this incredibly sad time."
Channel 4 has said that it will also share a tribute to Bernicoff before the show's Christmas special on Sunday.
Hours before broadcasting the Christmas Eve episode, featuring the series' memorable moments of 2017, Channel 4 confirmed in a statement: "His passing will be marked in the announcement before the programme airs."
Tania Alexander, the creator of Gogglebox, added: "So deeply saddened at the passing of our dear, dear Leon. He was and always will be the grandfather of
#gogglebox - an absolute star who always made me laugh with his sharp wit and unshakable opinions. Much love and strength to June and the Bernicoff family."
Singer Liam Gallagher also paid tribute to the Gogglebox star.
The Wall of Glass singer, who featured in a special charity episode of the show with his son and mother earlier this year, tweeted: "RIP Leon Gogglebox as you were LG x."
Presenter and Strictly Come Dancing 2016 champion Ore Oduba also posted his tribute to his "absolute favourite" character.
He wrote: "So sad to hear about Leon's passing. An absolute favourite in our house. His and June's love after 60 years marriage such a beautiful example to all of us... sending June and the family lots of love at this time of year @LeonAndJune."
Coronation Street and I'm A Celebrity ... Get Me Out Of Here! star Jennie McAlpine also shared her condolences, writing on Twitter: "So sad to hear about lovely Leon. He was a total £gogglebox delight. Thinking of his dear June."
Radio star Sara Cox wrote: "So funny, so sharp, thanks for the laughter and the tears Leon. Love to June and all the family," while Jeremy Vine responded: "Can't believe Leon has gone."
"Sleep well Leon," added The Great British Bake Off star Candice Brown.
Her Dancing On Ice co-star and singer Cheryl Baker posted: "Absolutely devastated that £Leon from £Gogglebox has died. I loved him, he was my fave! RIP you lovely, funny man. Sending hugs to £June at this terribly sad time xxx."
Actor and The Death Of Stalin writer David Schneider paid tribute to Bernicoff's "gentle" nature, writing: "Sad to hear about Leon from Gogglebox. In a world that's gone to arse he seemed such a gentle, honest soul and still so in love with June. £RIP."