Leading Massachusetts health insurers and state regulators squared off in court Thursday in their dispute about acceptable health insurance premiums for a pivotal sector of the local economy: small-business owners.

The insurers argued the state's decision last week to reject nearly all of their proposed 2010 premium increases will cause "destabilizing" losses for them. The state said the insurers fundamentally misunderstand both the rate rejection and the way to resolve their dispute.

During a two-hour hearing in Suffolk Superior Court, an attorney for Blue Cross Blue Shield of Massachusetts and five members of the Massachusetts Association of Health Plans asked Judge Stephen Neel to issue a temporary injunction overruling the state's decision.

Attorney Dean Richlin also asked that the companies be allowed to collect the new premiums they had proposed be effective April 1 while a trial is held on the matter.

He said that requiring them to collect premiums at April 2009 rates, as he contended the state has ordered them to do, was "grossly unsound" and would create losses of more than $100 million in the next eight months.

"These are losses that will quickly mount up, and for some number of companies, the immediate losses will be destabilizing," Richlin said.

The No. 2 Senate Democrat accused Republicans Wednesday of refusing to accept the finality of health care changes, a day after President Barack Obama signed the most sweeping medical system remake since Medicare.

"This is a political exercise for too many on the other side of the aisle," said Sen. Dick Durbin. "We're going to tell our people back home, 'It's time to govern. It's time to lead.' "

Durbin appeared Wednesday on a nationally broadcast interview show with South Carolina's Jim DeMint, who had said last year he believed the health care overhaul would turn out to Obama's "Waterloo."

"America doesn't want a broken presidency," countered Durbin, D-Ill.

DeMint did not back down, saying "Americans are very angry," not only with the substance of the sweeping health care bill Obama signed into law Tuesday, but also with the process Democrats used to muscle it through Congress.

The pair swapped barbs on NBC's "Today" show as the Senate entered a second day of debate on a package of fixes to the new health law. These legislative adjustments were demanded by House Democrats as their price for passing the mammoth overhaul legislation that will extend coverage to 32 million uninsured Americans over the next decade.

With the stroke of President Obama’s pen, his health care overhaul — the most sweeping social legislation enacted in decades — became law on Tuesday.

Mr. Obama affixed his curlicue signature, almost letter by letter, to the measure, the Affordable Health Care for America Act, during a ceremony in the East Room of the White House, surrounded by House Speaker Nancy Pelosi, Senate Democratic Leader Harry Reid and a raft of other lawmakers who spent the past year on a legislative roller-coaster ride trying to pass it. Aides said he would pass out the 20 pens he used as mementoes.

The ceremony included two special guests: Vicki Kennedy, the widow of the late Senator Edward M. Kennedy of Massachusetts, who had been a driving force for health care legislation before his death last year, and Connie Anderson, the sister of Natoma Canfield, the Ohio cancer survivor whose struggle to pay skyrocketing health insurance premiums became a touchstone of Mr. Obama’s campaign to overhaul the system.

Mr. Kennedy’s son, Representative Patrick Kennedy of Rhode Island, was also there, carrying a gift for the president: a copy of a bill his father introduced in 1970 to provide national health insurance. On it, the younger Mr. Kennedy had written a personal message to Mr. Obama.

President Barack Obama said on Friday he expected a tough vote this weekend, but Democrats were poised to make history when the House of Representatives votes on his healthcare overhaul bill.

"Right now we are at the point where we are going to do something historic this weekend," Obama told a raucous audience at George Mason University, as Democratic congressional leaders scrambled to round up support for the plan to revamp the $2.5 trillion medical industry.

"If this vote fails, the insurance industry will continue to run amok. They will continue to deny people coverage. They will continue to deny people care. They will continue to jack up premiums 40 percent or 50 percent or 60 percent as they have in the last few weeks," he told the rally.

"That's why they're pouring millions of dollars into negative ads. That's why they're doing everything they can to kill this bill," Obama said in a fiery speech.

"The time for reform is now," he said.

After more than a year of intense debate, the House is expected to vote on Sunday on the sweeping healthcare overhaul, intended to extend insurance coverage to 32 million uninsured Americans.

The bill has faced solid Republican opposition, and Obama and his fellow Democrats were struggling to ensure enough votes from Democrats, who hold a majority of seats in both houses of Congress, to ensure its passage.

President Barack Obama said on Thursday a report on his proposed legislation to overhaul the healthcare system showed it would reduce the nation's budget deficit over the long term.

House Democrats are pushing to the brink of passage a landmark, $940 billion health care overhaul bill that would simultaneously deliver on President Barack Obama's promise to expand coverage while slashing the deficit, a strategy aimed at attracting support from the party's fiscal conservatives.

The 10-year plan would provide coverage to more than 30 million people now uninsured through a combination of tax credits for middle class households and an expansion of the Medicaid program for low income people. Release of the legislation later Thursday sets the stage for a House vote on Sunday.

It would restructure one-sixth of the U.S. economy in the biggest expansion of the social safety net since Medicare was created in 1965. It would also impose new obligations on individuals and businesses, requiring for the first time that most Americans carry health insurance and penalizing medium-sized and large companies that don't provide coverage for their workers.

Hospitals and doctors, drug companies and insurers would gain millions of new paying customers, but they would also have to adjust to major changes. Medicare cuts would force hospitals to operate more efficiently or risk going out of business. Insurance companies would face unprecendented federal regulation. Health care industries would be hit with new federal taxes. Upper-income households would face a new tax on investment earnings.

A Scottish man is facing charges after the Philadelphia-to-London flight he was on made an unscheduled stop in Boston because he was allegedly being belligerent and disruptive.

A spokesman for Logan International Airport says John Alexander Murray of Glasgow was arrested shortly after US Airways Flight 728 landed at around 11 p.m. Monday. The plane departed for London two hours later.

Prosecutors say the 50-year-old Murray was blocking the aisle with his arm, which was in a splint. They say he would not move his arm, despite several requests from the crew, and demanded to be taken back to Philadelphia.

He is scheduled to be arraigned Tuesday in East Boston District Court on a charge of interfering with a flight crew.

A look at key issues in the health care debate:

THE ISSUE: Why do medical costs increase at a rate faster than inflation?

THE POLITICS: Health care spending over the past year increased by 3.2 percent even as overall consumer prices dropped 2.1 percent. That's not unusual in the United States, where health care spending rises at rates substantially higher than inflation. Analysts agree on any number of reasons for the increases, but tend to disagree on which cause is most responsible. Among the reasons:

_Americans get too much unnecessary care — too many tests, treatments and hospitalizations that do not improve their health. The reasons for this vary: Many doctors have a financial interest in new technology, doctors and hospitals fear malpractice lawsuits and patients are indiscriminate consumers because they are shielded from health care costs through insurance or government health plans.

_Easy access to expensive new medical technologies.

_Inefficient health insurance companies with high administrative costs that don't have anything to do with actual health care.

_Unhealthy living habits that strain the system, including smoking and obesity.

WHAT IT MEANS: Curbing the rising costs of health care is at the heart of the current debate on overhauling the nation's health care system. Rising costs have placed Medicare, the federal government insurance program for the elderly, on an unsustainable trajectory that would be responsible for exploding government deficits. At the same time, employers and their workers have met with rising health insurance costs that are straining business and family budgets.