"This is about your future and which one of us can produce for you, protect your jobs and your environment and give you affordable health insurance," he said. "It's clearly me. You don't really know this other guy. That's the fight we're in."
Lamont used his appearance on "This Week," to reintroduce himself to the voters.
"Ned Lamont's a guy who started up a business from scratch," he said. "Ned Lamont's a guy that thinks that George Bush has taken this country in the wrong direction. And I believe it's time for the Democrats, and I offer a clear and positive alternative to the Bush agenda."
Bouyed by support from the Internet's liberal blogs, Lamont has made a steady climb from distraction to legitimate challenger.
"There are hundreds of blogs out there on every single subject there is," he said. "Many of the blogs are supportive of us. We don't have anything to do with those blogs. Yes, they're supportive. Yes, we know many of those people. There have been a lot of posts -- a post is like a letter to the editor. I don't control what these people put on these things."
According to the latest Quinnipiac University poll released on Thursday, Lamont has opened up a 54 to 41 percent lead over Lieberman among likely Democratic primary voters. Analysis of the Quinnipiac statistics by the ABC News' polling unit points out that Lamont's lead relies on a 2-1 advantage among liberals who, in the 2004 Connecticut primary, accounted for 59 percent of all voters, indicating that while Lieberman may fare well in a general election, his woes are particularly troublesome in a primary dominated by liberal voters.
Lamont embraced the liberal label.
"I am a liberal -- but I mean a liberal, I think, a progressive," Lamont said. "I think if you're an entrepreneur in business -- you see a problem, you want to address it head on, you want to solve it -- I think then you're a progressive in government. And right now I think we have a government that's not dealing with real issues. So yes, I'm a liberal and I'm a progressive."
Lieberman called Lamont a "chameleon changing to suit the environment."
"I think he's really a center-right Democrat, but he's become the most doctrinaire liberal Democrat in America because he senses, he sniffs the realization of an ambition, which is to become a United States senator," Lieberman said.
"I put my loyalty to the Democratic Party and the principles of the Democratic Party up against Ned Lamont any day," Lieberman said.
Lamont "has gone through a total transformation," he added.
Lamont, who calls Republican President Teddy Roosevelt one of his role models, said Lieberman has been a good senator and a good Democrat in the past.
"I just think he's wrong on the big issues that are important right now," Lamont said.
For his part, however, Lieberman sees this primary race through the lens of only one issue.
"Ned Lamont may have talked about some other issues," Lieberman said. "He may nitpick and distort my record, but it's very clear from everything that we see and hear that he's essentially asking the people about the Democratic primary to send a message against George Bush and the Iraq war. And I'm saying to them: I ain't George Bush, and I have delivered for you over 30 years."
Lamont, who approaches the Tuesday primary with a surprising lead against a strong incumbent, said that "it's time for a change of course in Iraq."
"I hope this primary on August 8, that people turn out. They're going to be able to send a message loud and clear that the people of Connecticut want to change course there," Lamont said. "I hope that sends a message to the November election, and I'll be able to act upon that as a U.S. senator."
George Stephanopoulos' entire interviews with Lieberman and Lamont can be viewed at "This Week's" Web page at www.abcnews.com.