My understanding is that the White House's position has always been that it favours a public option, thinks a public option is a good idea, wants to see a public option in a bill, and also wants to sign a health reform bill that passes congress, covers the uninsured, and reduces long-run health cost inflation relative to current baseline projections.

BBC: Obama may soften healthcare plan

To make the debate on NHS reform comprehensible, and the claims testable against evidence, what we need is some form of baseline scenario that explains the level of productivity improvement needed to keep health costs below double their present cost.

BBC: Health Bill: Where's the strategic argument?