WASHINGTON – The health care proposal to be posted on the White House Web site today will be a broad ”starting point” for discussion at this week’s televised health care summit, not a detailed piece of legislation, a top administration official said Sunday.

Senior aides to President Obama said the document will propose changes to the health care legislation that passed in the Senate late last year, including lower taxes on expensive insurance plans and higher subsidies for working families to get health coverage. The changes could add up to $200 billion in costs to the $871 billion Senate bill.

But the online materials will not address a controversial question — whether Democratic leaders would use a parliamentary procedure known as ”reconciliation” to try to pass health care changes without the usual 60 votes in the Senate, officials said.

”This proposal aims to be a starting point for the conversation on Thursday,” said a senior White House aide who requested anonymity because the document was not public yet. ”We are going in with an open mind. It will not be very detailed. We are not dealing with process now, just substance.”

Republicans have accused the president of using Thursday’s summit as political theater, and they had raised the prospect of not attending. But the Senate’s top Republican promised Sunday that he and his members are ”ready to participate,” while accusing the Democrats of being ”arrogant.”

”You know, they are saying, ‘Ignore the wishes of the American people. We know more about this than you do. And we’re going to jam it down your throats no matter what,’ ” Senate Minority Leader Mitch McConnell, R-Ky., said on ”Fox News Sunday.”

White House communications director Dan Pfeiffer said in response that ”the upcoming meeting is an opportunity to get beyond oft-repeated and completely false talking points like these.”

McConnell dismissed the idea of a GOP boycott of the summit, saying that ”we’re discussing the sort of the makeup of the room and that sort of thing, but yeah, I intend to be there and my members will be there and ready to participate.”

McConnell said, however, that his party will continue to oppose Democrats if they try to use reconciliation.

”We think a better way to go is to, step by step, move in the direction of dealing with the cost issue, targeting things like junk lawsuits against doctors and hospitals, interstate insurance competition, small-association health plans,” he said.

Health care dominated discussions at the National Governors Association for a second day Sunday. Four leaders of the organization issued a plea to Obama and Congress for states to have a greater voice in the deliberations over health care. But they had no plan to offer, nor did they ask to be included Thursday.

A White House official noted that Obama is meeting with the governors for an hour today.

The appeal from the governors appeared mostly to be an effort to urge Congress and the president to work harder to find consensus. It also was an acknowledgment that the NGA, usually an island of cross-party cooperation, has become divided along party lines over health care.

”It’s important that as the discussion continues in the national capital that governors be at the table,” Vermont Gov. Jim Douglas, a Republican and the NGA chairman, said at a hastily called news conference that caught other governors by surprise.

The appeal appeared to be an implicit slap at political leaders in Washington and at the messy process to produce a health care bill, which has been stalled since the surprise election last month of Sen. Scott Brown, R-Mass.

Several participants in the governors luncheon Sunday said there is broad agreement on a list of incremental reforms that could be sent to Congress and the president with the governors’ blessing. But two participants said a number of Democratic governors balked at the idea of turning that list into a formal recommendation from the NGA.

The disagreement spilled into the Sunday talk shows.

Mississippi Gov. Haley Barbour, a Republican, urged Democrats to abandon their comprehensive health care efforts in favor of smaller, targeted changes. Speaking on ”Fox News Sunday,” Barbour said the bills pushed by Democrats would ”drive up the cost of health insurance. We shouldn’t put a huge unfunded mandate on states that would make me raise taxes $150 million in Mississippi.”

But California Gov. Arnold Schwarzenegger, speaking on ABC’s ”This Week,” urged members of his party to work with Democrats to make changes in the health care system.

”I think that Republicans should be at the table with health care reform and bring their ideas, whatever it may be,” Schwarzenegger, a Republican, told host Terry Moran. ”This is what compromise is all about. You’ve got to have two opposing point of views. You try to bring them together and try to find out where is the sweet spot here.”