The veteran star is the third contestant to leave the show without the public voting them off, following Katie Price and Camilla Dallerup's exits from the jungle.
On last night's show, Hamilton told Kim Woodburn that he was considering leaving, admitting that he was only on the programme for fun.
"There are people who are starting careers and I'm at point where this is fun to do. I'm not going to go head-to-head, so I'm thinking about leaving, pulling out tomorrow," said the 70-year-old.
His comments came after he made an emotional phonecall to his girlfriend Barbara. "I miss you more than you can imagine, and I'm holding on as long as I can here," he told his partner. "I love you and miss you [Barbara]. I may be home in a minute, who knows what will happen?"
Hamilton was one of the favourites to win the show, which ends on Friday.