LOS ANGELES–It’s vasectomy day at the Planned Parenthood health center near the University of Southern California. The lobby is bursting with men, women and children.

In the adjacent administrative offices that used to be part of a garment facto

ry, Monday morning is always hectic, vasectomy day or not. In one of two call centers, about a dozen employees are hunched over telephones, scheduling appointments and providing information. They handle an average of 2,000 calls a day.

Those employees are supposed to move to a larger room soon, reflecting the growing demand here for Planned Parenthood’s services — up 10 to 15 percent from last year, said Sue Dunlap, the Los Angeles chapter president.

But that move may be put on hold if Congress follows through on a threat to cut off all federal funding for Planned Parenthood, which amounts to $360 million a year nationwide. That money is used to provide family-planning assistance for low-income women, including contraception and testing for sexually transmitted diseases.

Rep. Mike Pence, R-Ind., sponsored an amendment to eliminate the funding because, he said, Planned Parenthood focuses on providing abortions. Though he acknowledged that the organization provides useful services, he said using government money to help pay for them freed up more funds for abortion services. Laws already prohibit direct federal funding for abortion.

Pence’s amendment passed the House in February but was defeated in the Senate in March. The dispute over the issue contributed to the impasse that threatened to shut down the federal government until a last-minute deal Friday night.

The focus on abortion frustrates Dunlap, who worked for various Planned Parenthood chapters for 13 years before assuming the top job at the Los Angeles affiliate last month. Abortions account for 3 percent of the patient visits to Planned Parenthood clinics nationwide; the most popular services are screenings for breast and cervical cancer, screening and treatment of sexually transmitted diseases, and contraception.

“This has been an attack on basic health care,” she said.

Roughly one-third of Planned Parenthood’s $1.1-billion national budget comes from the federal government, with the balance provided by contributions, bequests and fees for clinic services. Losing $360 million a year would probably mean reducing clinic hours and cuts in some programs, said spokesman Tait Sye.

But, he said, the biggest impact would be felt by clients with Medicaid, because Planned Parenthood would no longer be able to accept that form of payment.

Planned Parenthood was founded as a birth control clinic 95 years ago by Margaret Sanger, a nurse in New York City. The organization now treats more than 3 million people a year, with 2.5 million visits for contraceptives, said Cecile Richards, president of Planned Parenthood Federation of America. One in five U.S. women has used a Planned Parenthood health center, its surveys show.

The organization includes more than 80 chapters that are run independently and establish their own budgets but that must follow Planned Parenthood guidelines such as submitting to periodic reviews and following medical guidelines and quality-of-care standards, Sye said. These affiliates oversee more than 800 health centers nationwide.

As providers of abortion, the organization and its health centers are frequent targets for protest. The Pence amendment has attracted many supporters, including Minnesota Rep. Michele Bachmann, former governors Mike Huckabee and Mitt Romney and former vice presidential candidate Sarah Palin — all potential candidates for the Republican presidential nomination.

Leaders of several national medical organizations, lawmakers and Planned Parenthood administrators defended the organization at a rally in Washington last week.

More than 30 health-care groups — including the American Congress of Obstetricians and Gynecologists, the American Nurses Association and the National Medical Association — have sent letters to Congress in support of continued funding for the organization, and an editorial in the New England Journal of Medicine with the rueful title “Women and Children Last” criticized family-planning budget cuts.

Planned Parenthood health centers support obstetricians and gynecologists by providing care in underserved areas, said Dr. Maureen Phipps, an OB/GYN on the faculty at the Warren Alpert Medical School of Brown University.

“People don’t understand how vital Planned Parenthood is to preventive services including immunizations, contraceptives, preventive health, STD screening and treatment, cervical cancer screening, screening for high blood pressure,” she said. “Those services are often overshadowed by the controversial issues. But this is 90 percent of what Planned Parenthood does.”