The Senate rejected a key proposal repealing and replacing ObamaCare on Tuesday night, as senators start a days-long debate on healthcare.

Moments after a bitterly divided Senate finally voted to move forward with the long-promised legislation to repeal and replace Obamacare, Republicans brought their first plan up for a vote late Tuesday night only to watch it fail at the first hurdle, according to media reports.

The Senate blocked a wide-ranging proposal by Republicans to repeal much of Obamacare and replace it with a more restrictive plan as suggested by President Donald Trump, Time Magazine reported. Senators voted 57-43 to reject the plan in the first vote on an amendment to the bill known as the Better Care Reconciliation Act (BCRA). Those voting "no" included nine defecting Republicans, the report said.

Nine Senate Republicans voted no on BCRA. That makes it really hard to see any GOP-only replacement passing, ever. https://t.co/B1cDbDycfx — Caitlin Owens (@caitlinnowens) July 26, 2017

Republican senators Susan Collins, Bob Corker, Tom Cotton, Lindsey Graham, Dean Heller, Mike Lee, Jerry Moran, Lisa Murkowski and Rand Paul voted against the repeal and replace proposal on the procedural hurdle, according to The Hill. No Democrats voted for it.

The proposal was the first amendment to get a vote after senators took up the healthcare bill that cleared the House. But it was widely expected to fail because it needed 60 votes as the Congressional Budget Office (CBO) didn't analyse the proposals that were packaged in with BCRA. Tuesday night's vote doesn't prevent the Republican leadership from offering another repeal and replace amendment, or another version of BCRA, The Hill reported.

Dubbed “Trumpcare 3.0” by Democrats, the bill was the Senate’s stab at crafting a replacement of the Affordable Care Act, also known as Obamacare. It would have gutted more than $700 billion from Medicaid and sharply cut the tax credits available for low income people to buy health insurance, TPM reported.

The bill included a controversial provision drafted by Senator Ted Cruz that would allow insurers to offer plans that don’t cover basic care such as doctor visits and prescription drugs. The provision was never scored by the non-partisan CBO, and a glowing analysis of it by the Department of Health and Human Services was found to be seriously flawed, the report said.

According to The Hill, Cruz acknowledged ahead of the Tuesday's vote that the amendment wasn't likely to be approved, but appeared optimistic that Republicans would be able to get to an agreement before a final vote this week.

"I will say the bill before the Senate ... is not likely to pass tonight but I believe at the end of the process the contours within it are likely to be what we enact, at least the general outlines," Cruz said ahead of the vote, according to the report.

Cruz said he expects his amendment to end up in the final version of the healthcare bill. "I believe we will see the consumer freedom amendment in the legislation that is ultimately enacted," he said.

Another vote on an amendment that would repeal much of Obamacare is expected on Wednesday.

For Republicans, the procedural vote ended the day on a sour note, hours after a more triumphant scene in the Well of the Senate.

Lawmakers from both parties gave Senator John McCain a standing ovation after he turned up for the vote despite his brain cancer diagnosis and recent surgery.