Sen. Tom Harkin (D-Iowa) publicly whipped colleagues Wednesday against voting for amendments to a healthcare fixes bill.

On a conference call, Harkin, the chairman of the Senate Health, Education, Labor and Pensions (HELP Committee, urged fellow Democrats to vote against all amendments to the health bill, no matter how enticing they may seem.

Any amendments, Harkin said, provide opponents of the legislation "an opportunity to make more mischief and kill the bill."

"We need to make sure that none of our Democratic senators are tempted to vote for any of the Republican amendments," he said. "No more opportunities for Republicans and special interests to kill this bill."

The Senate is currently debating a bill under budget reconciliation rules that would make final changes to the healthcare bill that was signed into law on Tuesday by President Barack Obama. Republicans have sought to raise points of order and amendments to the bill, which would send the bill back to the House for another vote.

Harkin urged colleagues against going "wobbly in the knees" even on the most enticing amendments, including a public option, for which the senator has been a vocal proponent.

"If a public option is offered as an amendment today, I will vote against it," he said.

The health committee chairman said he expects the Senate to begin its marathon votes on amendments as early as 5 p.m. on Wednesday, at a clip as quick as four votes per hour.

"We've come too far. The end is in sight. Let's get this over with," he said. "Stick with us for the next several hours and lets get this job done."