WASHINGTON — President Barack Obama and congressional Democrats today rushed to strike final deals on historic health care legislation.

The goal was to send the tax and spending provisions of the package to the Congressional Budget Office later today for a cost estimate, a necessary step before votes are cast. It was not clear if negotiators would pull that off.

"I don't know," House Speaker Nancy Pelosi said when asked if the informal deadline could be met. "We're going to go back to the White House and talk about some other issues this afternoon and probably have a better idea as to when we can send something."

Obama and congressional negotiators have participated in marathon talks in recent days. Hours of discussion ended after 1 a.m. today and resumed in the afternoon at the White House.

Among other issues, lawmakers were searching for more revenue sources and cost controls in the bill after striking a deal with organized labor to weaken a proposed tax on high-value insurance plans.