A Republican plan to replace Obamacare will not be voted on this week, effectively signalling its collapse.
The party leadership said the bill would not come to the Senate floor after a third “no” vote emerged.
Susan Collins said she could not back the “deeply flawed” bill, despite a call from President Donald Trump and promises of money for her state.
It was a major blow for the president and Republican leadership, who have made Obamacare’s repeal a top priority.
US Senate Republicans have released a revamped health bill in a bid to rally their divided party around its seven-year campaign to repeal Obamacare.
The plan retains key Obamacare taxes on the wealthy, while allowing insurers to offer less coverage and imposing sharp cuts to healthcare for the poor.
The new bill aims to woo Republicans of conservative and moderate factions.
Congress is delaying its summer holiday in a bid to overturn former President Barack Obama’s 2010 legislation.