Sen. Mikulski (D-Md.) urged Maryland Gov. Larry Hogan (R) this week to help convince congressional Republicans to lift federal spending limits. (Steve Ruark/AP)

Sen. Barbara A. Mikulski said this week that Republicans in Congress risk derailing plans for Maryland’s light-rail Purple Line if they don’t lift spending caps that could limit the federal money available for the project.

Mikulski (D), Maryland’s senior senator and the ranking Democrat on the Senate Appropriations Committee, sent a letter to Maryland Gov. Larry Hogan (R) on Monday asking him to help persuade GOP lawmakers to end the limits.

“Without a new federal budget deal that lifts the discretionary budget caps for domestic and defense spending, Maryland’s ongoing economic recovery and business growth, including the Purple Line, could be put in jeopardy,” Mikulski wrote. “That is why I need your assistance in reaching out to House and Senate leadership to work on a budget deal that lifts the spending caps.”

Hogan, who had not replied to the letter as of Friday, has given no indication that he will appeal to individual Republicans in Congress. Instead, his staff suggested that Maryland’s members of the U.S. House and Senate — nine Democrats and one Republican — need to secure the federal contribution themselves.

“Marylanders are weary of the dysfunction in Washington and are eager to see their representatives put aside partisanship and get things done,” Hogan spokesman Matt Clark said.

Hogan has asked the federal government to contribute $900 million toward the 16-mile light-rail project, which would stretch between Bethesda and New Carrollton. He also committed $168 million in state money, and Montgomery and Prince George’s counties together have pledged more than $340 million.

Twice this summer, he asked Mikulski, Maryland’s other senator and its eight representatives to work to secure the federal funds.

Mikulski helped lock down an initial federal contribution of $100 million in a short-term spending bill that Congress approved for 2015.

She requested another installment of $100 million in the Senate’s 2016 transportation bill. But she said the funding is in doubt because of the ongoing across-the-board spending cuts known as sequestration, which took effect automatically after Congress failed to reach a deal to reduce expenditures in 2011.

Mikulski’s letter came during a battle over federal spending and talk of a possible government shutdown if Congress can’t reach a deal by the end of the month, when existing appropriations expire. A lapse in funding would force federal agencies to close — at least partially — for the second time since 2011.

The resignation of House Speaker John A. Boehner on Friday appears to have ended the possibility of an immediate shutdown, with Republicans saying the House would vote next week on a stopgap funding measure without any controversial attachments.

But that means future budget battles will be in the hands of a new Republican leadership.

On Monday, 46 Democratic state lawmakers from Maryland and Virginia sent a letter to Republican leaders in the House and Senate urging them to “put politics aside” to avoid a shutdown.

The letter said a funding lapse would have dire consequences for their states, which have some of the nation’s highest concentrations of federal workers and contractors.