In his first public remarks since Thursday’s bipartisan, bicameral meeting between congressional leaders and the White House, Senate Minority Leader Mitch McConnell (R-Ky.) took aim at the administration’s proposed $6.5 billion in spending cuts.

“The latest proposal is unacceptable and indefensible” to Republicans, McConnell said in a Senate floor speech Friday morning. He said White House proposal simply held to the status quo.

“It’s time for the Washington Democrats to get serious,” he said.

In a floor speech later, Senate Majority Whip Dick Durbin (D-Ill.) pushed back against the House Republican plan, arguing that it would make draconian cuts to medical research among other programs.

“It is so shortsighted, and it’s an indication that when they came to write the budget, the House Republican leadership didn’t focus thoughtfully” on the impact their cuts would have, Durbin said. The Republican argument, he said, is that “if you cut government spending, it’s going to help no matter what you cut. Not true.”

The Senate is slated to vote early next week on two competing budget plans, according to congressional aides. Neither budget proposal is expected to pass. Rather, the vote is expected to set the stage for further negotiations between congressional leaders and the White House on a measure that would keep the federal government funded through September.

Expected to be brought to the floor is the plan passed by the House last month, which would slash $61 billion from across federal agencies. The measure includes cuts that are strongly opposed by Senate Democrats, such as amendments that would defund Planned Parenthood and educational programs and curtail federal environmental regulations.

The other measure, put forth by the White House after Thursday’s meeting with congressional leaders, would include more than $6 billion in cuts that have yet to be laid out in detail.

Neither plan is expected to garner the 60 votes necessary to avert a filibuster, but their failure would demonstrate that neither is tenable to the full Senate. That would likely pave the way for compromise, allowing leaders of both parties to return to their respective bases and make the case for greater or lesser cuts.

Congress has until March 18 to reach a deal to keep the federal government funded. Earlier this week, Obama signed into law a stopgap plan that would avert a shutdown at the end of the week. Democrats argue that they have met Republicans halfway on spending cuts, while Republicans contend that the Democrats’ plan would not be any different from current spending.