House Democratic leaders worked furiously to nail down final votes before a scheduled weekend vote on its plan to reform the U.S. healthcare system.

Democratic head counters said they didn't have the 218 confirmed votes necessary to pass the bill, but expressed confidence they'd exceed that number by the time it comes up for a vote Saturday evening, The New York Times reported Friday.

Among other things, the $1 trillion bill would extend healthcare to 96 percent of the U.S. population and create a government-run health insurance option.

"We have a historic opportunity for us to, again, provide quality healthcare for all Americans," House Speaker Nancy Pelosi of California said. "It's something that many of us have worked our whole political lifetimes on."

While Democrats pressed their cause inside, opponents of the House measure rallied outside, where participants were encouraged to tell their lawmakers to vote against it, the Times said.

Rep. Michele Bachmann, R-Minn., the rally's organizer, called the package the "greatest threat to freedom that I have seen in the 19 years I've been in Washington." Bachmann, 53, is in her second two-year term in Congress, and was a state lawmaker and local school board member before that.