WASHINGTON – Millions of children across the country, including thousands in Maine, would lose their health insurance if the federal program paying for their coverage expires Sept. 30.

In recent weeks, Congress has sought to reach an agreement to continue the State Children’s Health Insurance Program, known as SCHIP. The 10-year-old program is designed to provide health insurance for children in families who earn too much to qualify for Medicaid but not enough to afford private insurance.

In early August, the Senate and House separately passed bills renewing SCHIP and increasing its funding, but the two bills differ in the amount of money to be spent. A compromise bill has now tentatively been hammered out.

“A person’s entire life can rest on the quality of the health care received during childhood,” Sen. Olympia Snowe, R-Maine, who voted in favor of renewing the program, said Wednesday. “Every family wants to provide the most advanced, comprehensive health care to their children and Congress has an obligation to reach an agreement.”

The Senate and House negotiators have agreed to renew the program for five years and increase its funding by $35 billion over that period, increasing the five-year total to $60 billion, to be paid for by an increased tax on tobacco sales. President Bush has called for an increase of $5 billion.

The increased funds are intended to pay for rising health care costs but also to be used by states for outreach programs to enroll children who are already eligible for the program but not participating.

In Maine, nearly 11,000 children are eligible but unenrolled in the program, according to Elinor Goldberg, president of Maine Children’s Alliance, a family advocacy group.

In a phone interview, Goldberg said, “14,000 children are covered, but there are another 11,000 who are eligible but not enrolled.”

But Bush has threatened to veto the SCHIP bill that is most likely to land on his desk because of what he called at a June press conference a “massive expansion” of government health care through SCHIP. More recently, as Congress has come closer to reaching an agreement on the legislation, Bush has repeated his threat to veto the bill.

Michael Leavitt, the Health and Human Services secretary, has said the president supports reauthorization of SCHIP, just not expansion of the program.

“What he objects to is using this program or its reauthorization as a chance to expand dramatically the number of people who have federal health care,” Leavitt said in a July 30 interview on public television.

Separately from the debate over the bill’s spending levels, the administration and some states have been at odds over those states’ attempts to expand the number of eligible children.

In spite of the president’s resistance to the legislation, both of Maine’s Republican senators voted in favor of expanding the children’s health insurance program.

“There has been widespread agreement in Maine that the Children’s Heath Insurance Program has been successful in providing health care. It is an investment that is well worth it,” Sen. Susan Collins said in a phone interview Tuesday.

Collins also said she spoke to a White House liaison Tuesday to express her disapproval of the threatened presidential veto.

“I am very concerned about the president’s threat to veto. I think it would be a tremendous mistake,” Collins said. “I can’t believe the president would veto a program that benefits low-income children.”

Snowe agreed.

“Our constituents want real solutions on covering the uninsured, not partisan gridlock on one of the most critical issues facing our nation,” Snowe said in a statement. “I would strongly encourage the president to reconsider his short-sighted veto threat and work with Congress to extend health insurance to millions more deserving children.”

U.S. Reps. Tom Allen, D-Maine, and Michael Michaud, D-Maine, also support increasing funding for SCHIP.

“SCHIP and Medicaid provide a lifeline to hardworking Maine families who don’t have employer-provided coverage or are unable to afford the skyrocketing cost of private insurance,” Michaud said in a statement Wednesday.

Allen said Wednesday he expected Congress to vote on the final bill sometime next week.

Health care has increasingly become a financial burden on Americans, as premiums continue to increase and fewer employers offer full coverage to employees and their families.

Costs are especially high in Maine, according to a national report released by the Centers for Medicare and Medicaid Services, the federal agency that administers the SCHIP program.

Maine ranks third in the country in money spent annually on health care per person. Maine residents spend on average $6,540 annually compared to the national average of $5,283, according to the report.

SCHIP allows states to use funding to pay for health insurance for children in families earning up to 200 percent of the federal poverty level. The federal poverty level is currently $20,650 for a family of four.

While other states have requested federal approval to offer coverage to families earning up to 300 percent or 400 percent of the federal poverty level, Maine has not.