WASHINGTON (Reuters) - U.S. President Donald Trump will hurt low-income Americans by doing away with Obamacare subsidies and make it harder for him to engage in bipartisan talks with Democrats as Congress edges toward a possible government shutdown, lawmakers said on Sunday. The White House has announced that the Republican administration will stop paying billions of dollars to insurers to help low-income consumers meet out-of-pocket medical expenses, as part of the president’s step-by-step effort to dismantle the Affordable Care Act, Democratic former President Barack Obama’s signature healthcare law. The expected loss of cost-sharing subsidies, estimated to be worth $7 billion this year and $10 billion in 2018, has prompted worries about insurance market chaos and undermined the prices of insurer and hospital company shares. By antagonizing Democrats who support Obamacare, Trump’s actions could also lead to political turmoil over spending in December, when Republicans hope to put the final touches on a sweeping tax reform bill.   Republican Senator Susan Collins, who has opposed Trump-backed legislation to repeal and replace Obamacare, warned that the president’s move will also affect the ability of vulnerable low-income people to access healthcare and afford out-of-pocket medical costs.  “I’m very concerned about what the impact is going to be for people,” Collins said on CNN’s “State of the Union”. “The funding that is available under the cost-sharing reductions is used to subsidize their out-of-pocket costs. And if they can’t afford their deductible, then their insurance is pretty much useless.” Asked if Trump’s actions would hurt Americans, she replied: “I do believe that.” Last week, the president also offered an invitation for Democratic leaders to come to the White House to negotiate on healthcare.   But House of Representatives Democratic leader Nancy Pelosi showed little interest on Sunday.  “We’re a little far down the road for that,” Pelosi said on ABC’s “This Week” program. Pelosi indicated that the president’s actions and continued White House pressure to fund a wall on the U.S.-Mexico border could make it harder for Republicans to win Democratic cooperation in December, when a current government spending measure is due to expire.  “He wants to negotiate the healthcare bill by repealing the Affordable Care Act and building a wall? No,” Pelosi said. “The Republicans have the majority. They have the signature of the president. It’s up to them to keep government open.” Collins and Pelosi see a bipartisan path on healthcare in discussions on possible legislation between Republican Senator Lamar Alexander and Democratic Senator Patty Murray. Republican Senator Lindsey Graham told CBS’ “Face the Nation” that Trump has also encouraged Alexander to get a bipartisan deal but also wants any future healthcare bill to reform the current system.  “The president is not going to continue to throw good money after bad, give $7 billion to insurance companies unless something changes about Obamacare that would justify it,” Graham said. “It’s got to be a good deal.” 