US President Barack Obama called on lawmakers today to take one last plunge later this week and approve a major overhaul of the US health care system, his top domestic priority, according to dpa. The House of Representatives is set to vote on a final piece of legislation that aims to cut costs, place new curbs on health insurance companies and extend coverage to about 30 million Americans that lack health insurance. "We need courage," Obama told a townhall gathering in Ohio as part of his final push to drum up support for the controversial reforms, amid uncertainty over whether his fellow Democratic lawmakers had enough support to pass the bill. Opposition Republicans have vowed to do everything in their power to block the legislation, and opponents from around the country are planning one final protest in Washington on Tuesday. Some moderate Democrats have also opposed the reforms as too costly and imposing too much government regulation over the largely private health sector, which comprises about 17 per cent of the US economy. Obama has argued the reforms will end abusive practices by insurers and limit rises in premiums. "In the end, this debate is about far more than politics. It comes down to what kind of country do we want to be," Obama said. The House could vote as early as Thursday, but talks may extend into the weekend. Despite strong majorities in the chamber, lingering disputes within the left-leaning Democratic Party have left leaders struggling to muster the 216 votes needed to pass the legislation. Obama last week agreed to postpone a trip to Asia later this week in order to continue lobbying lawmakers and the US public, which has been sharply divided during the long-running debate. Both the Senate and House passed differing versions of the health reforms late last year. Each chamber must now vote again to approve the same version before the bill can reach Obama's desk. If passed by the House this week, the bill will go back to the Senate, where Democratic leaders have promised to use a controversial procedural manoeuvre that allows them to approve changes with a simple majority rather than having to win over Republicans.