Republicans in the United States Congress have begun a bid to overturn the healthcare law signed by President Barack Obama in 2010.
A bill to repeal the law was formally unveiled on Monday evening. Republicans assume control of the lower house of Congress on Wednesday.
The bill is set to be voted on by the House of Representatives on 12 January.
But the BBC reports the vote is expected to be largely symbolic as Democrats retain a Senate majority and can block the move and the president could ultimately veto it.
The Republicans won sweeping gains in November's mid-term congressional elections in part by attacking the healthcare law, which is seen as too costly.
The healthcare law was approved in March last year, making it compulsory for Americans to buy medical insurance and illegal for insurance companies to deny coverage to customers with pre-existing conditions.
If, as expected, the repeal bid fails, the BBC reports Republicans will attack the law through other means, specifically by using congressional committees to cut off relevant funds.
Court challenges have also been lodged at state level.