White House officials on Thursday proclaimed the agreement with unions on taxing high-cost insurance plans a major victory for health care reform legislation, asserting that it improves on the policy included in the Senate bill and moves the House and Senate substantially closer to agreement.

“The president is pleased with the agreement,— White House Communications Director Dan Pfeiffer said in a teleconference with reporters. Pfeiffer said that by working with labor and business officials, negotiators had “made this a better provision in terms of policy.—

A senior White House official said on the call that the deal has moved the House and Senate “much closer— to an agreement. He called the insurance tax one of the “most potentially troubling issues between the House and Senate,— adding, “we’ve taken a big step toward a conclusion.

Nevertheless, talks continue on other matters in the bill, and White House officials could not say how they would make up the loss of expected revenues that will occur as a result of the deal.

A source familiar with the discussions said much of the progress on the insurance tax issue was made during discussions at the White House Wednesday between a group of union presidents and White House officials.

Leading the talks on the White House end was Deputy Chief of Staff Jim Messina, who has played a key role in the health care negotiations from the beginning. Vice President Joseph Biden also dropped in on the meeting to talk with union leaders.

A senior White House official on the teleconference said Obama would make the case to lawmakers that the agreement helps reduce health care costs while helping families. “We cannot do health care on the back of the middle class,— the official said, “and this deal achieves that.—