Mr Farage has even admitted that pro-Brexit MPs would lose a historic vote over Brexit in Parliament.
His admission has come as the Economists for Free Trade have predicted that Britain will gain £651bn from walking away from talks, costing the EU £507bn.
Mr Farage said: “The Remain side are making all the running.
“They have a majority in parliament, and unless we get ourselves organised we could lose the historic victory that was Brexit.
“The Leave groups need to regather and regroup because Remain is making all the arguments.
“After we won the referendum, we closed the doors and stopped making the argument.
“We no longer have a majority in parliament. I think we would lose the vote in parliament.”
Mr Farage’s remarks have also followed him earlier this week suggesting that he wanted a second referendum on the UK’s EU membership.
Appearing on Channel 5’s The Wright Stuff, he said: “What is for certain is that the Cleggs, the Blairs, the Adonises will never ever ever give up. They will go on whinging and whining and moaning all the way through this process.
“So maybe, just maybe, I’m reaching the point of thinking that we should have a second referendum on EU membership… unless you want to have a multiple-choice referendum which would confuse people.
“I think that if we had a second referendum on EU membership we would kill it off for a generation. The percentage that would vote to leave next time would be very much bigger than it was last time round.
“And we may just finish the whole thing off. And Blair can disappear off into total obscurity.”
However, the former Ukip leader has since sought to clarify his remarks, arguing while he doesn’t want another vote, a second referendum may be inevitable as the EU will offer Britain such a bad deal it will be rejected by Parliament, and the Government will not leave the union without a deal.
Writing for the Telegraph, Mr Farage said: “To be clear, I do not want a second referendum, but I fear one…