Congress is turning up the heat on President Obama to cut the backlog of Veterans Affairs disability claims, which has gone up by 2,000 percent while the agency’s budget has increased by 40 percent over the past four years.

A bipartisan group of House lawmakers is the latest to call upon the president to be more aggressive, sending a letter this week asking him to “take direct action.”

“We need direct and public involvement from you to establish a clear path to end the backlog once and for all,” said the letter by Reps. Mike Coffman, R-Colo., and Patrick Murphy, D-Fla.

The number of veterans waiting for overdue disability claims is now at 600,000 with the average wait for first-time filings at 317 to 327 days, according to the letter.

“In many cases, veterans have waited and continue to wait 800 days, 900 days and even more than 1,000 days,” Coffman and Murphy said in the letter, cosigned by 164 other House Democrats and Republicans.