UPDATE 4:38 P.M.: Coburn released his hold on the bill Thursday afternoon.

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A bill reforming the Freedom of Information Act (FOIA) could pass the Senate as early as Thursday, but at least one senator has placed a hold on the legislation.

The FOIA Improvement Act of 2014 has been "hotlined," meaning it is being considered for placement on the Senate’s unanimous consent calendar, where it could be passed without a lengthy debate.

The bill unanimously passed the Senate Judiciary Committee in November and would be the first major reform of the FOIA since 2007. Among other provisions, the legislation would codify President Obama’s requirement for federal agencies to act with a "presumption of openness" and weaken agencies’ leeway to withhold documents more than 25 years old.

However, Sen. Tom Coburn (R., Okla.) has placed a hold on the legislation for the moment, blocking it from placement on the unanimous consent calendar. Coburn’s office did not immediately return a request for comment.

Sen. Bob Corker (R., Tenn.) also placed a hold on the legislation but dropped his objections earlier Thursday.

A bipartisan group of senators, including Judiciary chairman Patrick Leahy (D., Vt.) and ranking Judiciary Republican Chuck Grassley (R., Iowa) are working to whip the bill and smooth out any objections within their caucuses.

The House unanimously passed a bipartisan FOIA reform bill introduced by Oversight Committee chairman Darrell Issa (R., Calif.) and Elijah Cummings (D., Md.) in February.