The former Conservative Party leader walked away from 10 Downing Street less than a month after the British people voted on June 23, 2016 to leave the European Union (EU) by a 52-48 margin, reports Xinhua news agency.
More than three years later, incumbent Prime Minister Boris Johnson has suggested that the UK will leave the EU on October 31 with ot without a deal.
In an in-depth interview on Friday with British newspaper The Times, Cameron said he recognized some people will never forgive him for holding a referendum, but he thinks a referendum was "inevitable".
"This issue needed to be addressed and I thought a referendum was coming, so better to try to get some reforms we needed and have a referendum.
"But I accept that effort failed. I do understand some people are very angry because they didn't want to leave the EU. Neither did I," he said.
Cameron admitted that he thinks about the referendum every single day.
"I worry desperately about what is going to happen next. I think we can get to a situation where we leave but we are friends, neighbours and partners. We can get there, but I would love to fast-forward to that moment because it's painful for the country and it's painful to watch," he added.
Cameron, in his interview, also accused Johnson and Cabinet Minister Michael Gove of behaving appallingly during the 2016 EU referendum campaign, saying they had left the truth at home.
He also said Johnson had expected Britain to vote to remain in the EU, adding that he hopes Johnson will manage to secure a deal with Brussels.
Cameron said he believes a second referendum might be the way forward.
The interview came ahead of the upcoming publication of his memoir "For The Record", which details the Brexit debate before, during and after the referendum.
( With inputs from IANS )