"The longer you wait [for approval] the more it costs the company," she said. "That is particularly true for a small company. Any delay can cause a huge cash flow issue."

In one indication of how important the issue is for the industry, pharmaceutical companies have stepped up the amount they are spending to lobby Congress, even as spending by other health care sectors has declined. Drug makers spent $69.6 million to influence lawmakers in the first quarter of this year, up 6 percent over the same period in 2011, according to the Center for Responsive Politics.

The Senate health committee passed the legislation on a voice vote late last month, a signal of bipartisan support. The only "no" vote came from Sen. Bernard Sanders, a Vermont independent who has previously objected to the fee legislation because it does not allow patients to buy drugs at a lower price from Canada.

Wyoming Sen. Michael B. Enzi, the top Republican on the health committee, has noted that there's been "good cooperation" on the issue, despite rancorous debates on other health care legislation.

"We need to enact user fee legislation in a timely manner," he said. "Patients, jobs and innovation depend on it."

The prognosis for the legislation is less clear in the Republican-controlled House of Representatives, where work on a similar measure recently was delayed. Several officials close to the negotiations said they believe the delay was needed to work out technical issues, not substantive ones.

The proposal faces opposition from some consumer groups over how medical devices are tested. For instance, manufacturers may receive an expedited review of a new product if it is similar to one already on the market — even if the original device was recalled. Lisa McGiffert, director of the Safe Patient Project, wants lawmakers to change that and give the FDA more latitude to scrutinize fast-track reviews.

"This is an industry that's going to explode in the next five years," McGiffert said of medical device manufacturers. "It's increasing in volume and increasing in complexity."

But the main concern for supporters is that the politics of a divided Congress could curb the bill's momentum, forcing another messy, last-minute political showdown this fall. It is the first time the drug fees have faced reauthorization in a presidential election year.

"The implications for this are quite positive for the state of Maryland," said Judy Britz, executive director of the Maryland Biotechnology Center, a state economic development agency. "But if the legislation were to run into any snags ... the implications would be really dire."