Negotiations over extending unemployment benefits for 1.3 million Americans stalled in the Senate Thursday, as Democrats and Republicans bickered over parliamentary procedure and how to cover the cost of the $6.5 billion extension.

Senate Majority Leader Harry Reid, D-Nev., introduced an amendment that would extend the benefits for the long-term unemployed through mid-November. It would be paid for with structural reforms to the program and by extending automatic budget cuts, known as sequestration, for an additional year. But Republicans balked, arguing that the budget cuts would put off for years, possibly indefinitely.

The real driver of the GOP opposition, however, appeared to be Reid’s decision not to allow votes on any Republican amendments to the extension legislation. The frustration boiled over Thursday afternoon as Reid and several Republicans became embroiled in a heated floor debate that centered on the Nevada Democrat’s leadership style. Absent votes on GOP amendments, Republicans said they would not deliver the support the bill needs to clear the 60-vote threshold before the Senate can take a final vote on it.

“I’m definitely a ‘no’ on cloture next week, obviously from what happened here today, unless something changes,” said Sen. Dan Coats, R-Ind., one of six Republicans who voted with Democrats earlier this week to advance the benefits extension package. “That change would have to come from the majority leader’s decision to allow us to have a say in what this bill looks like.”

Senate Democrats accuse Republicans of using the issue of amendment votes as a political stalling tactic, asserting that the proposal Reid unveiled to pay for the benefits extension reflects GOP priorities. New York Sen. Charles Schumer, the No. 3 Senate Democrat, said voting on multiple amendments is a counterproductive way to reach a bipartisan accord on this issue.

Democrats would prefer a three-month unemployment insurance extension that does not include off-setting budget cuts. They want the Republicans to make a single counteroffer that, with the Democratic proposal, would serve as a starting point for negotiations on the bill.

Thursday’s blow-up on the Senate floor over Reid’s decision not to allow votes on GOP amendments was reminiscent of how 2013 ended. Last month, Republicans expressed their discontent over a Democratic rules change that curtailed the filibuster by repeatedly using the parliamentary tools still available to them to slow the pace of legislation, including bills they otherwise supported.

Negotiations continue, however, and Democrats and Republicans who have been involved said there is still a chance they might bear fruit. The benefits extension legislation bill was co-authored by Sens. Dean Heller, R-Nev., and Jack Reed, D-R.I. Heller is the point person for the Republicans, but Reid, the majority leader, appears to have final say over what Democrat are willing to accept.

Barring an agreement late Thursday, it appeared the next possible day the Senate might vote on extending the benefits is Monday. The Republican-controlled House, meanwhile, is unlikely to support any bipartisan agreement that might emerge from the Senate, at least based on the current parameters for any deal that would attract enough GOP votes to clear the chamber.