U.S. Transportation Secretary Ray LaHood has called on Congress to pass a funding bill for the Federal Aviation Administration that would put some 74,000 people back to work.

The agency has been partially shut down since Saturday, after lawmakers failed to agree on an extension of its authority to operate.

Some 4,000 FAA employees have been furloughed. The shutdown has also affected construction projects that employ about 70,000 workers.

LaHood told reporters Thursday that the construction industry is already suffering from high unemployment and “this is not the time to be laying off 70,000 people.”

He noted the shutdown is costing the government some $200 million a week in uncollected taxes on air fares.

But he said air travel in the United States is still safe, because the laid-off FAA employees are researchers or other types of workers not involved in day-to-day air travel. He said all air traffic controllers went to work Thursday as usual.

Lawmakers failed to pass the funding for the FAA because of disputes between Democrats and Republicans on several issues. One major issue is a provision that would make it harder for airline and railroad workers to unionize. Another controversial provision would cut subsidies to airports in rural communities.