While moderate Democrats are insisting they will not vote for a health care reform bill with a public option, President Obama has an even bigger problem with his natural allies on the far left; they won't support reform unless the government run option is in the mix.

In truth, Obama's problem is not the public option per se but how well he can massage his base so that they will accept less than half a loaf on reform. According to Glenn Thrush of Politico , the president sounded a reassuring note to his far left friends on a conference call:

A coalition of liberal Democratic lawmakers came away from a conference call with President Obama this afternoon believing that the public option for health care is still very much in play.

But CNN is reporting that the White House is also preparing its own "contingency" bill as a backup plan if Congress veers too far left or can't get a deal on health care this fall. The White House, in negotiations with Sen. Olympia Snowe (R-Maine), is leaning much more heavily toward a "trigger" for the public option instead of mandating creation of the government insurance.

But Rep. Lynne Woolsey (D-Calif.), one of the leading voices of the Progressive Caucus, just released a statement on the call with Obama, saying they were confident Obama was still on their side.

"Caucus leaders expressed absolute commitment to the idea of a robust public option, and said they expect it to be part of any health care reform legislation," Woolsey's office said in a statement. "The president listened, asked many questions, and suggested that the dialogue should continue. A follow-up meeting between the president and caucus leaders will take place next Tuesday or Wednesday at the White House."

The groups on the phone call with Obama included the Congressional Progressive Caucus and the Tri-Caucus, which comprises the Congressional Black Caucus, Congressional Asian Pacific American Caucus, and Congressional Hispanic Caucus.