Sen. Joe Lieberman (ID-Conn.) said Monday evening that he would not stand in the way of Democrats’ attempts to extend tax cuts for the middle class while letting taxes on higher incomes grow.

Earlier in the day, Lieberman released a statement saying it was unwise to pass President Barack Obama’s plan to let taxes go up on individuals making more than $200,000 and couples making more than $250,000, while making permanent Bush-era tax cuts for middle- and lower-class taxpayers.

But when asked by reporters, Lieberman said he would not join in an expected GOP-led filibuster of the plan. The Senator caucuses with Democrats but supported the Republican presidential nominee, Sen. John McCain (Ariz.), in 2008.

“I believe that in the middle of this very fragile economy it’s no time to be raising anybody’s taxes, including the top income earners, but I would not therefore stop tax cuts for the middle class,” he said. “I think to me there’s very broad agreement on the middle-class tax cuts, therefore we ought to get it done and then we can argue about tax cuts for higher income.”

Sen. Ben Nelson (D-Neb.), however, indicated he might support a filibuster of a bill that allows taxes on the wealthy to go up, but he noted that he did not believe such a bill would come to the Senate floor.

Asked whether he would vote for a bill like the one Obama has outlined, Nelson said, “It would be very hard for me to support that.”

Besides Lieberman and Nelson, Democratic Sens. Jim Webb (Va.), Kent Conrad (N.D.) and Evan Bayh (Ind.) have expressed opposition to the president’s proposal. Senate Republicans insist they have the votes to filibuster such a measure.