WASHINGTON (AFP) - US President Barack Obama's Democratic allies got an unlikely vote of confidence Saturday, as a top Republican foe prematurely declared defeat in the fight over remaking US health care.

Mike Pence, the number three Republican in the House of Representatives, put a statement on his official Internet site denouncing final House passage of White House-backed legislation -- hours before the vote was expected.

Pence's office described the statement as coming "after the Democrat Majority in the House of Representatives passed HR 3962" -- the bill's designation.

"I am proud that all House Republicans stood by the American people in opposition" to the proposal, the statement quoted Pence as saying.

The error came hours before the divided House was to vote on the health care plan, with Democrats struggling to paper over intra-party feuds on volatile issues like abortion.