WASHINGTON (AFP) – President Barack Obama's plan to overhaul the US health care system got a major boost when a key US House of Representatives committee approved the measure.

Democratic leaders of the House Energy and Commerce Committee hammered out a compromise that saw the health care reform package -- Obama's main domestic priority -- approved 31-28 late Friday.

The move clears the way for a full House vote in September, when the legislators return from their August recess.

We have a historic opportunity to transform our health care system, said committee member Democrat Mike Ross from Arkansas after the vote.

White House press secretary Robert Gibbs described the committee approval as a big, positive step forward.

The House measure is aimed at providing health coverage for some 50 million Americans who lack insurance, and to restrain skyrocketing health care costs.

A health care reform bill however is not yet certain, as any measure approved in the House would have to be reconciled with whatever the Senate approves -- and key Senate Finance Committee members warned there was still much work to do.

Republicans have fiercely opposed Obama's plans, and opposition from conservative Democrats to a plan many consider too costly has weakened the president's sizeable majorities in both chambers.