GLENSIDE, Pa. - President Barack Obama accused insurance companies of placing profits over people as he sought to build public support Monday for swift passage of health care legislation stalled in Congress.

"Let's seize reform, the need is great," Obama said at an appearance that had the feel of a campaign rally.

Obama's pitch in this Philadelphia suburb, along with a stop in St. Louis on Wednesday, comes as the president begins an all-out effort to pass his health care proposals. The next two weeks will prove decisive, with the White House pushing for a vote in the House of Representatives by March 18, when Obama leaves for an Asia trip.

"How much higher do premiums have to rise before we do something about it?" Obama asked at Monday's appearance.

The United States is the only developed nation that does not have a comprehensive national health care plan for all its citizens. About 50 million of America's 300 million people are without health insurance. Most of those who are insured rely on their employers for coverage.

The president said dismissively that Republican critics in Congress say they want to do something about rising health care costs, but said they did not when they held power.

"You had 10 years. What happened. What were you doing?" he said to applause from an audience at Arcadia University.

Obama made his appeal as Democratic leaders in Congress worked on a rescue plan for sweeping changes in health care that seemed earlier in the year to be on the brink of passage. The two-step approach calls for the House to approve a Senate-passed bill despite opposition to several of its provisions, and both houses to follow immediately with a companion measure that makes a series of changes.

Obama's stated goal across more than a year of struggle has been to extend coverage to millions who lack it, ban insurance industry practices such as denying coverage on the basis of pre-existing conditions and cut costs.

Republicans dismissed Obama's argument instantly. "The American people have heard all this rhetoric from the president before, and they continue to say loudly and clearly they do not want a massive government takeover of health care," said House Republican Leader John Boehner of Ohio.

Obama has long identified the insurance industry as an obstacle to changes along the lines he seeks, but the administration's actions and rhetoric seem to have escalated in recent days.

The president's proposal would give the government the right to rein in excessive premiums increases - a provision included after one firm announced a 39 per cent increase in the price of individual policies sold in California. Separately, Kathleen Sebelius, the secretary of health and Human Services, convened a White House meeting with insurance executives last week, and followed up with a letter released in advance of Obama's speech.

It asked companies to "post on your Web sites the justification for any individual or small group rate increases you have implemented or proposed in 2010."

Full Democratic support is far from certain. Some party moderates are uneasy about the cost of the $1 trillion bill and its language on abortion, and some House Democrats are suspicious of whether their Senate colleagues would follow through on promises to work out the differences in the bills.

The Democratic plan includes greater consumer protections and a ban on discriminating against customers with pre-existing conditions. Small businesses also would receive a tax credit this year. The White House hopes the immediate changes created by the bill would give Democratic candidates a strong platform on which to campaign in the fall.

Though Obama has included some Republican proposals in his plan, Republicans have called for the existing bills to be scratched and for the process to start anew. Party leaders insist they're on the side of a public that doesn't want the government-controlled health care they maintain the president's plan would create.