"If the public option is in there, as a matter of conscience, I will not allow this bill to come to a final vote because I believe the debt can break America," he said.

Another is that the House bill includes the "public option", an idea that appeared to die during the summer but which Mrs Pelosi has given fresh life to.

While she voted for Mr Obama’s health-care bill, she opposed a public option, and she also opposed the union-friendly Employee Free Choice Act.