The worst kept secret in California politics is basically all but confirmed, as Governor Schwarzenegger issued a statement this afternoon promising to both veto the Democratic health care proposal and to call the Legislature back for a special session.

“I cannot sign AB 8 because it would only put more pressure on an already broken health care system,” said the governor in a written statement released to the media.

Schwarzenegger’s statement also confirmed that he will call a special session of the Legislature to address health care reform, and many presume a formal announcement will come soon. “We must keep working,” he said in his statement.

That being said, there’s a lot of uncertainty about what happens next.

For example, the governor’s press statement today lists numerous problems with the bill carried by Assembly Speaker Fabian Nunez and Senate President pro Tem Don Perata… not the least of which is that it doesn’t cover everyone who’s uninsured. Democrats say AB 8 would cover about two thirds of those in California who don’t have insurance.

And while there are a small number of people who also wouldn’t have been covered under the governor’s January healh reform framework, universal coverage is something he says at almost every public appearance.

Democratic leaders told reporters this morning they’re proud of their proposal. “This is a damn good bill,” said Senator Perata.

And Speaker Nunez suggested that while Democrats are more willing to talk about funding for health care in a special session, they’re not so flexible when it comes to the structure of health care reform. “We are not going to be willing to make a lot of movement,” he said, “in the area of the substance of the bill.”