WASHINGTON (Reuters) - U.S. Senator Lamar Alexander on Tuesday made the first move by a senior Republican to work with Democrats on repairing Obamacare after his party failed to repeal and replace the healthcare law, announcing work on bipartisan legislation to stabilize the individual health insurance market.

Alexander, who chairs the Senate health committee, urged U.S. President Donald Trump to drop his threat to cut government subsidy payments to insurers that make Obamacare plans affordable and to allow the payments through September. The senator also said fellow lawmakers should fund those payments for one year.

Alexander’s announcement followed the spectacular failure last week by Senate Republicans to pass their own repeal or replacement of the Affordable Care Act, former President Barack Obama’s signature domestic initiative also referred to as Obamacare.

The Tennessee Republican said the Senate health committee “will hold hearings beginning the week of September 4 on the actions Congress should take to stabilize and strengthen the individual health insurance market so that Americans will be able to buy insurance at affordable prices in the year 2018.”

The goal, Alexander said, would be legislation sponsored by both parties that would stabilize the insurance market and help lower premiums in 2018 for the roughly 18 million Americans who buy health insurance in the individual market, instead of getting insurance through an employer.

Trump, frustrated that he and Republicans have not been able to keep promises to repeal and replace Obamacare, has threatened to let the law implode, including by cutting off about $8 billion in subsidies that are used to make Obamacare health plans more affordable for low income Americans.

Insurers, who are finalizing their insurance premium rates for 2018, have asked Congress to guarantee that those funds will stay in place for the rest of this year and 2018. Without the subsidies, they say they will need to raise premium rates by about 20 percent.

Without an answer, insurers have filed preliminary rates based on different parameters: Some set rates that assumed the subsidies would be paid, others set rates that assumed they would not, and some submitted two different set of rates reflecting both outcomes.

Senator Patty Murray, the top Democrat on the health panel, welcomed Alexander’s statement and said she looked forward to working in a bipartisan manner to stabilize the healthcare market and reduce premiums.

In the House, a bipartisan group of 43 lawmakers on Monday called for Congress to quickly stabilize the individual insurance market by appropriating money for the cost-sharing payments and creating a stability fund for states.