U.S. House Speaker Nancy Pelosi speaks during her weekly press conference on Capitol Hill in Washington, D.C., the United States, on Aug. 13, 2020.Ting Shen | Xinhua News Agency | Getty ImagesThe Trump administration and Democratic leaders have scrambled to strike a coronavirus stimulus deal before the Nov. 3 election. On Sunday, Pelosi set a 48-hour deadline to reach an agreement.Writing to House Democrats, the speaker said she is “optimistic that we can reach agreement before the election.” Pelosi added that “we are writing [legislative] language” as talks continue, “so that we are fully prepared to move forward once we reach agreement.”She highlighted several lingering disputes, including a national testing strategy and state and local government relief. Pelosi also cited tax credit expansion, child care provisions and support for the U.S. Census as areas of disagreement.Even if Pelosi and Mnuchin can forge a deal, Senate Republicans will pose an obstacle to passing it. Most GOP lawmakers have backed only limited new spending to respond to the virus outbreak.The Senate GOP plans to vote on a roughly $500 billion aid package as soon as Wednesday. Earlier Monday, White House chief of staff Mark Meadows said Senate Majority Leader Mitch McConnell agreed to bring a potential bipartisan bill to the Senate floor “and actually have a vote.”Asked about Meadows’ comment, a McConnell spokesman pointed to a statement the Senate leader issued over the weekend. He said that, “if Speaker Pelosi ever lets the House reach a bipartisan agreement with the Administration, the Senate would of course consider it.”House Democrats most recently passed a $2.2 trillion bill, while the White House has put forward a nearly $1.9 trillion proposal.Congress has failed for months to approve new coronavirus aid as new virus infections hit levels unseen in months and the economy inches back from devastating shutdowns.This story is developing. Please check back for updates.Subscribe to CNBC on YouTube.