Senate Minority Leader Harry Reid (D-Nev.), center. on Tuesday criticized Senate Majority Leader Mitch McConnell (R-Ky.) for pushing to add a provision to the bill he said would keep corporate political spending secret. (AP Photo/J. Scott Applewhite)

Senate leaders on Tuesday said they are close to deal on a stop-gap spending bill that would prevent a government shutdown at the end of the month and provide funding to combat the Zika virus, but disagreements over last-minute details continued to hold up an agreement.

Negotiators continue to haggle over politically driven policy provisions that could be attached to the legislation as well as whether it should include emergency aid for the water crisis in Flint, Mich., and disaster relief for the recent flooding in Louisiana, aides said.

Congress must pass a stop-gap spending bill before the fiscal year ends Sept. 30 or risk a government shutdown. Both Senate Majority Leader Mitch McConnell (R-Ky.) and Senate Minority Leader Harry Reid (D-Nev.) have said they are confident a deal, which would include more than $1 billion in Zika funding, will be completed before the deadline, but the process is dragging out much longer than Republicans originally expected.

Senate GOP leaders had earlier hoped to wrap up the spending bill last week to allow vulnerable members to head home to campaign for reelection.

In a sign that a deal could be struck soon, the Senate late Tuesday voted 89 to 7 to move forward with the legislation that will serve as the vehicle for any deal, an important procedural step.

The current negotiations center around what each party will allow in the bill in exchange for their priorities.

Republicans are pushing for the legislation to include disaster relief for the recent flooding in Louisiana. Democrats do not oppose that proposal but have insisted that the package also include funding for the water crisis in Flint, Mich. The Senate passed a bipartisan aide package last week as part of a broader water bill, and Republicans want to give the House more time to consider funding for Flint.

“Clearly Flint is going to be taken care of, it will just be after the election,” said Sen. Bill Cassidy (R-La.). “Whereas [people in Louisiana] are trying to decide if they’re going to stay in their home or walk away from their mortgage.”

The latest GOP offer also included a provision sponsored by Sen. Ted Cruz (R-Texas) that would delay plans for the U.S. government to give up control over a global nonprofit that oversees the internet domain system.

Cruz told reporters that he is “cautiously optimistic” that it will be included in the final package.

But the Obama administration strongly opposes the delay and Democrats have been unwilling to accept that addition unless language is also included that would free the Export-Import Bank to approve more deals.

The bank is supposed to have a five-member board, but only two of the slots are currently filled due to Republican opposition to confirming more members. A third is needed to reach quorum to review deals over $10 million. The provision being pushed by Democrats would eliminate the need for a quorum.

Reid also attacked McConnell for pushing to keep in place language to prevent the Securities and Exchange Commission from requiring corporations to publicly disclose their political spending. Liberal advocacy groups and some Democrats have been pushing for greater disclosure in this area in recent years.

“We’re not going to have this bill [be] a pin cushion for McConnell’s desire to have nothing — nothing reported dealing with campaign spending,” Reid said. “Corporations can give under the present law lots and lots of money and it doesn’t have to be reported.”

A key hurdle to a deal on the overall bill was cleared earlier week when negotiators agreed to change language that would prevent Zika funds from going to Planned Parenthood clinics in Puerto Rico. Democrats strongly opposed that prohibition, but aides and lawmakers said this week that an agreement has been struck to carefully re-route the funds so that family planning clinics could access money to help prevent the spread of Zika through sexual activity.

There remains, however, some differences over what spending cuts should be included to help pay for the $1.1 billion Zika funds the bill would provide.