Sir Bruce Forsyth led tributes to Irish singer Val Doonican, who has died aged 88, describing him as a "lovely man".
Doonican died "peacefully" on Wednesday night, his family said.
The crooner was famous for his laidback style which helped him notch up a string of hits in the 1960s and 1970s, selling millions of records around the world.
He also fronted his own television programme, The Val Doonican Show, from 1965 to 1986, where he would appear each week in a rocking chair in one of his signature knitted sweaters as he sang classic pop songs in an easy-listening style.
Sir Bruce said: "It is very sad. He was always a lovely man to work with.
"He had the top television show on the BBC. He had the warmth, the voice and the sweaters. He was one of the warmest personalities I think we have ever had.
"I did his show and then he did a couple of my shows.
"He was a very warm person, and number one in his field. He brought a lovely warmth with his personality and was a very popular man."
The family said: "Until 87, he was as fit as a flea. It was just old age, I'm afraid - the batteries ran out."
Singer and actress Elaine Paige said on Twitter: "Sad to hear of Val Doonican's passing ... RIP Val" and posted a clip of the pair singing Can't Get Used To Losing You from 1983.
In a statement the family said: "He was a wonderful husband, father and grandfather and will be greatly missed by family, friends and his many fans."
Doonican was born in Waterford and began his musical career gigging in his home town and appearing on Irish radio.
He moved to England in 1951 to pursue his dream of cracking showbusiness but his big break did not come until more than a decade later when, in 1963, he appeared on Sunday Night At The Palladium.
His eight-minute slot changed his life and he was soon signed up for a record deal and offered his BBC show, which ran for more than 20 years.
Doonican notched up a string of hits in the 1960s and 1970s including Walk Tall, The Special Years, Elusive Butterfly and What Would I Be.
He retired from performing in 2009 after more than 60 years in showbusiness.
He died in Buckinghamshire and is survived by his wife Lynn, daughters Sarah and Fiona and grandchildren Bethany and Scott.
Adrian Walsh, an Irish comedian who opened for Doonican for four years, described him as "one of the greats".
He said: "Sometimes when you meet your heroes you are disappointed, but he exceeded all expectations.
"I've never met anyone who didn't like Val, he was just a joy and a gent to work with.
"He would have told a story for 40 years and every night it would be like the first time he told it. I used to say to young comedians, go and watch Val and how he tells a story. He was unbelievable.
"He was a great family man and a beautiful guy."
Tony Blackburn joined the chorus of broadcasters paying tribute, tweeting : "So sad to hear that Val Doonican has passed away. He was a lovely man and a true professional who I worked with on several TV shows R.I.P."