Republican leaders of the United States House of Representatives Monday night unveiled changes in a bill that is intended to replace Obamacare, the healthcare reform introduced by former President Barack Obama.

Internal disagreements over the bill have been threatening to derail the first big legislative initiative of President Donald Trump. The amendments are an attempt to sway wary conservatives and moderates, but a coalition of House hardliners said they were not persuaded.

Conservatives consider the changes insufficient and the moderates are opposed to leaving out millions of Americans without healthcare coverage.

The revised bill gives the states more power over the federal government to manage the reform.

It will also offer aid to elderly citizens, who will be among the largest groups to be affected by the rollback of Obamacare, for purchasing health insurance.

Changes to the bill include allowing states to impose work requirements on Medicaid recipients; granting a lump sum of federal Medicaid funding to states to do with as they wish; and immediately prohibiting any additional states from expanding the Medicaid program. The initial proposal allowed states to expand Medicaid until January 2020.

The amendment is the result of two weeks of aggressive negotiations. The House Republican leadership is racing to shore up support for the proposed health care overhaul before a planned vote on Thursday. Donald Trump will meet with Republicans on Capitol Hill on Tuesday morning to rally party members.    

For two weeks the Republicans have been negotiating the content of the bill before submitting it to vote, first in the House of Representatives, and then at the Senate, where they have a narrower majority and are likely to face more hurdles.

The country's non-partisan Congressional Budget Office has estimated that the Republican plan would leave 14 million people without healthcare coverage within a year, and the number could go up to 24 million in a decade.