David Cameron has accepted responsibility for instability in the UK since the 2016 Brexit referendum.
The former Prime Minister will be interviewed on ITV on Monday at 8pm.
In a clip from the interview shared ahead of its broadcast, the 52-year-old was asked if the decision to call the referendum haunted him.
Mr Cameron said: “Yeah, of course. You know, this is a huge decision for our country and I think we've taken the wrong path. As I've said, it can be made to work.
"If you're asking me, do I have regrets? Yes. Am I sorry about the state the country's got into? Yes.
"Do I feel I have some responsibility for that? Yes. It was my referendum, my campaign, my decision to try to renegotiate.
"And I accept all of those things and people, including those watching this programme, will have to decide how much blame to put on me.
“I cannot put it more bluntly than this - I accept that that attempt failed.”
During the interview, Mr Cameron also speaks candidly about the death of his son Ivan, aged six.
The Guardian came under fire for an editorial it published which said the father had only felt "privileged pain".
