CNN  — 

Top House Democrats are preparing to move a $2 billion supplemental funding bill to address US Capitol security to the floor later this month, despite some outstanding questions – and reservations – among Republicans and even some Senate Democrats about the spending.

House Appropriations Chairwoman Rosa DeLauro and the other leaders of the House and Senate Appropriations committees have started negotiating on what a funding supplemental for Capitol security should look like, though they have not yet reached an agreement yet on what should go in the bill – or how to address policy questions like what to do with fencing around the Capitol.

DeLauro said Thursday at the Brookings Institution that she plans to hold a briefing about the bill next week for Democrats, suggesting that House Democrats are intent to push forward with the bill, which stemmed from the March recommendations of a task force established to review security at the Capitol at the request of House Speaker Nancy Pelosi following failures on January 6.

“We’re going to move forward on it in the next few weeks,” the Connecticut Democrat said.

It’s still not clear, however, whether Republicans will be on board with the proposal – and even Senate Appropriations Chairman Pat Leahy, a Vermont Democrat, has expressed concerns about the House Democrats’ plans to bolster funding for security.

House Majority Leader Steny Hoyer, a Maryland Democrat, said in a letter to lawmakers on Wednesday that the House would take up the funding package the week of May 17 – “if it is ready” – a key caveat that acknowledges the bill is not yet finalized.

Hoyer also said the House could take up legislation that week to establish an independent commission to investigate the January 6 attack on the Capitol, another priority Pelosi has pursued. But unlike the supplemental bill, where the two parties are talking, there’s been a standoff between Pelosi and House Minority Leader Kevin McCarthy and Senate Minority Leader Mitch McConnell over the commission proposal, as Republicans have insisted that the scope of the commission also encompass violence that occurred last year during protests of police brutality.

A senior Democratic aide confirmed to CNN that although Hoyer had mentioned that the security supplemental and the measure on a commission investigating January 6 could come to the floor at the same time, they are separate bills.

DeLauro said the briefing for House Democrats on the supplemental, which she and the six subcommittee chairs involved in drafting the legislation would lead, would likely occur on Monday, so that members can “know what’s going on and ask their questions before we take the bill to rules and then take it to the floor.”

It’s been four months since the violent insurrection at the Capitol, and the supplemental would represent Congress’ first major effort to fund improvements to physical and personnel security upgrades to protect the Capitol complex. Retired Army Lt. Gen. Russel Honoré, who spearheaded the task force effort to recommend improvements to Capitol security, called for retractable fencing around the complex, hundreds of new Capitol Police officers, a quick-reaction Capitol Police force on standby when Congress is in session and even background checks on all congressional staff.

The senior Democratic aide confirmed to CNN that the supplemental, which is expected to cost roughly $2 billion, will address many of the core recommendations in Honoré’s report but neglected to share specifics of what the bill will include.

As negotiations are ongoing, sources close to the talks tell CNN there is bipartisan consensus that the supplemental should add Capitol Police officers to the force. But while Honoré recommended a retractable fencing system be installed at the Capitol, there’s resistance among lawmakers to a permanent fencing system, one Democratic aide said.

Leahy has raised specific concerns over the size and scope of the security supplemental.

“We’re talking,” he told reporters last month. “I told everybody, step back and let’s see exactly what we need. If we need money, of course, the money will be there. But let’s not just spend the money and then ask what we do with it.”

Leahy has said that he wished an independent commission could tackle the security situation at the Capitol before appropriations were made.

“I would have felt much better that way, before we gave money,” Leahy said.

Republicans have also yet to sign off on the proposal. A Senate GOP aide said their side had only seen funding numbers on the supplemental, adding that Republicans have not seen much to justify the spending or any language to accompany the figures. The aide also suggested that Democrats were trying to expand the scope of the supplemental.

But DeLauro has argued she wants to keep the funding bill narrow, noting on Thursday, “Supplementals can become Christmas trees, and that we’re not going to do. We are trying to avoid that like the plague.”

Even though there is some talk of members trying to add legislation to the supplemental because it is considered a “must-pass bill,” a source involved in the negotiations said that was unlikely because House and Senate Appropriations committee leaders are united in the measure being narrow and clean.

One Democrat pushing for the supplemental to include more than just physically securing the Capitol is Rep. Jim Langevin of Rhode Island, who also wants the legislation to secure funding for cyberspace.

“I’d like to see additional funding to secure Americans in cyberspace, including funding for the Office of the National Cyber Director that was requested by President Biden in the American Rescue Plan, but then cut for procedural reasons. A $15 million investment in the new Office of the National Cyber Director, which I helped to create in last year’s defense bill, would immediately move the needle in protecting all Americans in this new domain,” Langevin said in a statement to CNN.

Last month, DeLauro said the funding package would “improve intelligence collection and review, bolster the capacity and training of the Capitol Police, and make physical security improvements to the Capitol Complex.”

“The Appropriations Committee is working to address these critical areas. When Congress returns to Washington, we will act to ensure the safety of the Capitol and everyone who works there,” she said.

Pelosi told CBS’ “Face the Nation” last month: “We’ll put it forth when it is ready, and it is just about ready now.”

The traditional path for an emergency supplemental would be for the bill to bypass committee and go straight to the floor, but a Democratic aide tells CNN a decision hasn’t been made about the process yet.