Former Sen. Joe Lieberman shared on Sunday a warning to both major parties against the appeal of recoiling to to the polar extremes of their base following a bitter election year.

To the Democratic Party in particular, which not only failed to regain either chamber of Congress but also lost the White House, Leiberman said he thinks there will be a "real attempt by the left-left" to take command of the party.

"It's not the party I worked so hard for when Bill Clinton was president," Lieberman said on John Catsimatidis' radio show "The Cats Roundtable." Lieberman was a Democratic senator from Connecticut from 1989 to 2006, when he became an independent.

This year's election saw an insurgent candidate for the Democratic nomination, Sen. Bernie Sanders, pushing a far-left progressive agenda, put up a strong primary challenge against Hillary Clinton. She ended up winning the nomination, but not before the former secretary of state shifted some of her proposals in a leftward direction, which included a party platform with many of the progressive ideas for which Sanders fought.

"Both parties better watch out not to go back to the extremes — left and right — and instead start working with each other. ... The public wants both parties ... to work together and solve ... problems," Lieberman added.

The 2000 Democratic vice presidential nominee also commented on how he thinks President-elect Trump will improve U.S. relations with Israel.

"[Trump] values Israel's independence. He values Israels's friendship. And he will protect Israel's security," Lieberman said.