Two more Senate Democrats called for extending tax cuts for all earners—including those with the highest incomes—in what appears to be a breakdown of the party's consensus on the how to handle the expiration of Bush-era tax cuts.

Sen. Kent Conrad (D., N.D.) said in an interview Wednesday that Congress shouldn't allow taxes on the wealthy to rise until the economy is on a sounder footing.

Sen. Ben Nelson (D., Neb.) said through a spokesman that he also supported extending all the expiring tax cuts for now, adding that he wanted to offset the impact on federal deficits as much as possible.

They are the second and third Senate Democrats to come out publicly in recent days in favor of extending all the tax breaks for the time being. Sen. Evan Bayh (D., Ind.) made similar comments last week.

"As a general rule, you don't want to be cutting spending or raising taxes in the midst of a downturn," Mr. Conrad said. "We know that very soon we've got to pivot and focus on the deficit. But it probably is too soon to cut spending or raise taxes."