In an interview published today, Lord Owen states that he is "completely at home" with Tony Blair's leadership and suggests that New Labour is a natural extension of the Social Democratic Party that he helped to found in 1983.
The former Foreign Secretary claims he was close to joining Labour before the last election and gives a strong hint that he is now on the verge of signing up.
Lord Owen's comments are guaranteed to stir up resentment among Labour backbenchers who dubbed him a traitor when he left the party in 1983 to set up the SDP.
He is described as an Independent Social Democrat and sits on the cross benches in the House of Lords, but would become a Labour peer if he rejoined the party.
"I have only used the word `never' once. I would never be a Conservative. Actually, I could use it twice. I would never be a Liberal. I am not going to say `never' about Labour," he says in the New Statesman magazine today.
Lord Owen reveals for the first time that he would have joined Labour before the general election if there was a danger of the Tories winning.
"Logically I should have joined. I'm completely at home with New Labour. I didn't want to campaign against John Major, who had been good to me. If Labour had looked as if it might lose, I would have joined and fought for them."
In an interview that marks his return to domestic politics after a period of self-imposed silence, the former SDP leader also said that he gets on well with Mr Blair and even appeared to take some of the credit for New Labour's emergence. "There was a logical development from SDP to New Labour and I think it would be fair to say that Blair understands my arguments," he said.
"The fight for more market-based economic policies started inside the SDP in 1983. It was a fight opposed by Roy Jenkins, Shirley Williams and Bill Rodgers. We fought and won. They tried to get me to support unilateralism. I fought and won."
Lord Owen, who heads New Europe, a lobby group opposed to the UK joining the single currency, also suggested that he and Mr Blair are equally sceptical about the prospect of an early referendum on the euro after the next general election.