Senate Budget Committee Chairman Kent Conrad (D-N.D.), a member of the Senate’s bipartisan “Gang of Six” that is working on a comprehensive deficit-reduction plan, said that any plan that will bring down the country’s debt needs to happen this year or may potentially not happen at all.

“If it doesn’t happen this year, it’s certainly not going to happen next year, so it’s really got to happen now,” Conrad told ABC News’s Jon Karl in an interview on the Capitol subway.

The Senate’s Gang of Six, which includes Conrad and Sens. Tom Coburn (R-Okla.), Mark Warner (D-Va.), Saxby Chambliss (R-Ga.), Dick Durbin (D-Ill.) and Mike Crapo (R-Idaho), has been working for months on a plan that would hew closely to the proposals made last year by President Obama’s bipartisan fiscal commission.

But there’s also a new deficit-reduction group in town – a bipartisan “Gang of Seven” that includes members from both chambers as well as Vice President Biden. The group, which Obama called for in a speech at George Washington University this month, will hold its first meeting at Blair House on May 5 with the aim of producing a deficit-reduction plan by the end of June.

Conrad, who is not running for reelection in 2012, told ABC that even in light of the newly formed deficit-reduction group, he still believes the original Gang of Six is “critically important.”

“I would not have spent hundreds and hundreds and hundreds of hours of my time if I didn’t think there was a realistic prospect. ... I think it’s an important piece of the puzzle here,” he said.

He declined to say whether the group was near agreement on a plan. “Can’t say for certain, because we have a rule: Nothing’s decided until everything is,” Conrad said, in a refrain that was reminiscent of House Speaker John Boehner’s (R-Ohio) mantra during the negotiations earlier this month on averting a government shutdown.

Meanwhile, another member of the Gang of Six, Tom Coburn, told conservative radio host Laura Ingraham on Thursday that the group’s plan would probably not result in “significant” tax hikes.

“There’s no plan to have a significant tax hike on anyone,” Coburn said, according to The Hill. He later added that the group’s proposal would probably include a broader tax-reform plan similar to that proposed by Obama’s fiscal commission, of which Coburn was a member.

“Will some people pay increased taxes? I’m sure they will,” he said.

A Washington Post-ABC News poll released Wednesday showed that 59 percent of Americans believe the best way to reduce the deficit is through a combination of cutting spending and increasing taxes, although 53 percent of respondents opposed a proposal such as the deficit commission’s, which would slightly raise taxes on all Americans and slightly reduce Medicare and Social Security benefits.