Republicans in the US House of Representatives have introduced a revised version of their plan to replace the Affordable Care Act (ACA), also known as Obamacare, on Monday night - three days before the house votes on whether or not to pass the bill.

The Thursday vote takes place on the seven year anniversary of former president Barack Obama signing the ACA, but the Republican replacement, named the American Health Care Act (AHCA), has not been without contention from within the party that promised it.

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The changes show that the more conservative elements of the party who risked scuppering the bill have had their concerns heard. One amendment states the right to require able-bodied people on Medicaid without dependants to work while another gave the option of receiving Medicaid funding as a block sum rather than a per-capita amount.

Further amendments bring forward the repeal of ACA taxes to 2017 instead of 2018.

The hard-line conservative 'Freedom' caucus has been the GOP leadership's main hurdle with the legislation, the right-wing group of lawmakers arguing that the AHCA does not do enough to repeal Obamacare.

Republican leadership may be worried about the political costs of such a drastic move though, with the popularity of the ACA reaching new heights as the repeal talks have taken place. Influential conservative pressure groups however have not been quiet in their rejection of a bill they call 'Obamacare-lite'.

But do they have the votes?

Though the revisions were meant to assuage these demands, the conservatives don't seem to have been bought off. House Freedom Caucus chairman, Mark Meadows, told reporters that the changes were not enough. "There are some small tweaks that are good tweaks, but there's not substantial changes in the manager's amendment that would make anybody be more compelled to vote for this."

Meadows said that the group would not be taking an official position on the revised bill but said that he did not think the legislation had enough votes to hit the 216 that the GOP leadership needs to pass the bill to the Senate.

A report by the nonpartisan Congressional Budget Office estimated that the initial bill would have left 52 millions Americans uninsured by 2026, 24 million more than are estimated to be left without health coverage by then under Obamacare.