A Senate committee on Wednesday abruptly postponed the planned markup of a key election security bill that had bipartisan support and would have imposed new audit requirements on states.

The markup of the Secure Elections Act, authored by Oklahoma Republican James Lankford and Minnesota Democrat Amy Klobuchar, is “postponed until further notice,” the Senate Rules and Administration Committee said on its website. 

The bill had the backing of several GOP lawmakers, including Richard M. Burr of North Carolina, Susan Collins of Maine and Lindsey Graham of South Carolina, as well as Democrats such as Mark Warner of Virginia, Kamala Harris of California and Martin Heinrich of New Mexico.

But a senior Republican lawmaker, Sen. Richard C. Shelby, objected to the bill’s provisions expanding the federal role in elections. 

“I have problems with that,” the Alabama senator said. “My problem is that heretofore, for the most part, the states and the counties and some local governments have funded and taken control and run the ballot box, so to speak, state-by-state.”

Shelby sits on the Rules panel and is the former chairman. He is the current chairman of the Appropriations Committee. 

“This is a big step for the federal government moving in,” Shelby said, before emphasizing that criticism of additional federal involvement was not an expression of opposition to enhancing security. “We’re all concerned about the integrity of the ballot box,” he told reporters.

A committee aide said there’s not yet enough broad support among the GOP to get the bill to the floor.

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“In order for a truly bipartisan election security bill to reach the floor, additional majority support is necessary,” the aide said. The aide was optimistic that Wednesday afternoon’s closed briefing for all senators on election security by the director of national intelligence, Dan Coats, could help the process of developing bipartisan legislation.

The postponement comes a day after Vermont Secretary of State Jim Condos, who’s also president of the National Association of Secretaries of State, told reporters on Tuesday he was worried about changes in the bill text that would impose stringent audit requirements on state election officials. Condos said the proposed changes amounted to an unfunded mandate being imposed by Congress on state officials.

The bill text the committee had planned to consider would have required each state and jurisdiction to conduct a post-election audit of each federal election by examining a random sample of ballots to “establish high statistical confidence in the election result.” The bill defined federal election to include primary contests.

Condos told reporters that although Vermont and other states had planned to audit the results of federal elections including presidential and congressional races, the requirement to conduct audits of primary contests would impose additional costs and resources on states, and some states would have to pass new legislation to make such audits possible.

Democratic senators who back the bill had wanted to provide as much as $250 million in funds along with the audit requirements to help states cover the additional costs, but the move was being opposed by Republican lawmakers, one senate aide speaking on the condition of anonymity said.

Klobuchar said she was “disappointed” by the committee’s decision to postpone.

In a statement, Klobuchar said the bill had wide bipartisan support and would require all states to conduct post-election audits to validate results, require all states to have paper ballot backup, and require the Department of Homeland Security to immediately notify states of any breach of security.

The original bill had required a risk-limiting audit, a rigorous type of audit that is considered the gold standard, but would have required such an examination only from those states accepting federal dollars, and would have asked for pilot projects to study the viability before imposing a 50-state requirement.

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Lawmakers subsequently changed that stipulation to require all states to conduct a statistically significant audit, and Klobuchar had planned to offer an amendment adding $250 million in funds to help states with conducting such audits, the aide said.

Condos previously backed the legislation and testified in June before the Senate Rules and Administration committee in support of post-election audits, telling lawmakers that “requiring a paper ballot with a robust post-election audit should be considered critical.”