The ex-Rochester and Strood Tory MP admitted his switch, announced on the eve of the final Tory party conference before the 2015 general election, came with “enormous personal risk”.
But he said he felt increasingly unable to honour promises made by the Tories more than four years ago, including on cutting immigration and localising power.
He has faced an onslaught of criticism from his former Conservative party colleagues since his defection, with some openly accusing him of lying about his plans to defect.
Andrew Mackness, chairman of the Rochester and Strood Conservatives, said Mr Reckless had agreed to join a Tory campaign bus the day before he quit.
But in an interview with BBC Radio Kent, Mr Reckless said that had the Tories found out about his plans in advance, he would have been attacked in “the most vicious, vicious way”.
He said: “You cannot announce these things in advance and what the Conservatives would have liked me to have done is to have told them so that they could have launched a media onslaught on me ... rather than me explaining the positive reason of why I wanted to join Ukip and why I wanted to keep the promises of my constituents.”
He added: “I’m running an enormous personal risk. I may be a footnote in history. I may be wrong. Perhaps the people of Rochester and Strood don’t feel as I do.
“Perhaps they don’t feel let down. Perhaps they are not worried about the Government breaking its promises.
“It’s a big risk. I think I have a fighting chance but I may lose. I will take my case to the electorate here and the people I have worked for and done as much as I possibly could over the last four and a half years.
“I will ask them. They will make the decision.”